nilfs2: fix missing initial short descriptions of kernel-doc comments

Update some kernel-doc comments that are missing the initial short
description and fix the following warnings output by the kernel-doc
script:

 fs/nilfs2/bmap.c:353: warning: missing initial short description on line:
  * nilfs_bmap_lookup_dirty_buffers -
 fs/nilfs2/cpfile.c:708: warning: missing initial short description on line:
  * nilfs_cpfile_delete_checkpoint -
 fs/nilfs2/cpfile.c:972: warning: missing initial short description on line:
  * nilfs_cpfile_is_snapshot -
 fs/nilfs2/dat.c:275: warning: missing initial short description on line:
  * nilfs_dat_mark_dirty -
 fs/nilfs2/sufile.c:844: warning: missing initial short description on line:
  * nilfs_sufile_get_suinfo -

Link: https://lkml.kernel.org/r/20240816074319.3253-9-konishi.ryusuke@gmail.com
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

fs/nilfs2/bmap.c

@@ -349,7 +349,7 @@ int nilfs_bmap_propagate(struct nilfs_bmap *bmap, struct buffer_head *bh)
 }
 
 /**
- * nilfs_bmap_lookup_dirty_buffers -
+ * nilfs_bmap_lookup_dirty_buffers - collect dirty block buffers
  * @bmap: bmap
  * @listp: pointer to buffer head list
  */

fs/nilfs2/cpfile.c

@@ -704,9 +704,15 @@ ssize_t nilfs_cpfile_get_cpinfo(struct inode *cpfile, __u64 *cnop, int mode,
 }
 
 /**
- * nilfs_cpfile_delete_checkpoint -
+ * nilfs_cpfile_delete_checkpoint - delete a checkpoint
- * @cpfile:
+ * @cpfile: checkpoint file inode
- * @cno:
+ * @cno:    checkpoint number to delete
+ *
+ * Return: 0 on success, or the following negative error code on failure.
+ * * %-EBUSY	- Checkpoint in use (snapshot specified).
+ * * %-EIO	- I/O error (including metadata corruption).
+ * * %-ENOENT	- No valid checkpoint found.
+ * * %-ENOMEM	- Insufficient memory available.
  */
 int nilfs_cpfile_delete_checkpoint(struct inode *cpfile, __u64 cno)
 {
@@ -968,21 +974,15 @@ static int nilfs_cpfile_clear_snapshot(struct inode *cpfile, __u64 cno)
 }
 
 /**
- * nilfs_cpfile_is_snapshot -
+ * nilfs_cpfile_is_snapshot - determine if checkpoint is a snapshot
  * @cpfile: inode of checkpoint file
  * @cno:    checkpoint number
  *
- * Description:
+ * Return: 1 if the checkpoint specified by @cno is a snapshot, 0 if not, or
- *
+ * the following negative error code on failure.
- * Return Value: On success, 1 is returned if the checkpoint specified by
+ * * %-EIO	- I/O error (including metadata corruption).
- * @cno is a snapshot, or 0 if not. On error, one of the following negative
+ * * %-ENOENT	- No such checkpoint.
- * error codes is returned.
+ * * %-ENOMEM	- Insufficient memory available.
- *
- * %-EIO - I/O error.
- *
- * %-ENOMEM - Insufficient amount of memory available.
- *
- * %-ENOENT - No such checkpoint.
  */
 int nilfs_cpfile_is_snapshot(struct inode *cpfile, __u64 cno)
 {

fs/nilfs2/dat.c

@@ -271,18 +271,15 @@ void nilfs_dat_abort_update(struct inode *dat,
 }
 
 /**
- * nilfs_dat_mark_dirty -
+ * nilfs_dat_mark_dirty - mark the DAT block buffer containing the specified
+ *                        virtual block address entry as dirty
  * @dat:      DAT file inode
  * @vblocknr: virtual block number
  *
- * Description:
+ * Return: 0 on success, or the following negative error code on failure.
- *
+ * * %-EINVAL	- Invalid DAT entry (internal code).
- * Return Value: On success, 0 is returned. On error, one of the following
+ * * %-EIO	- I/O error (including metadata corruption).
- * negative error codes is returned.
+ * * %-ENOMEM	- Insufficient memory available.
- *
- * %-EIO - I/O error.
- *
- * %-ENOMEM - Insufficient amount of memory available.
  */
 int nilfs_dat_mark_dirty(struct inode *dat, __u64 vblocknr)
 {

fs/nilfs2/sufile.c

@@ -840,21 +840,17 @@ int nilfs_sufile_resize(struct inode *sufile, __u64 newnsegs)
 }
 
 /**
- * nilfs_sufile_get_suinfo -
+ * nilfs_sufile_get_suinfo - get segment usage information
  * @sufile: inode of segment usage file
  * @segnum: segment number to start looking
  * @buf:    array of suinfo
  * @sisz:   byte size of suinfo
  * @nsi:    size of suinfo array
  *
- * Description:
+ * Return: Count of segment usage info items stored in the output buffer on
- *
+ * success, or the following negative error code on failure.
- * Return Value: On success, 0 is returned and .... On error, one of the
+ * * %-EIO	- I/O error (including metadata corruption).
- * following negative error codes is returned.
+ * * %-ENOMEM	- Insufficient memory available.
- *
- * %-EIO - I/O error.
- *
- * %-ENOMEM - Insufficient amount of memory available.
  */
 ssize_t nilfs_sufile_get_suinfo(struct inode *sufile, __u64 segnum, void *buf,
 				unsigned int sisz, size_t nsi)