appletalk: Fix atalk_proc_init() return path

Add a missing return statement to atalk_proc_init so it doesn't return
-ENOMEM when successful.  This allows the appletalk module to load
properly.

Fixes: e2bcd8b0ce6e ("appletalk: use remove_proc_subtree to simplify procfs code")
Link: https://www.downtowndougbrown.com/2020/08/hacking-up-a-fix-for-the-broken-appletalk-kernel-module-in-linux-5-1-and-newer/
Reported-by: Christopher KOBAYASHI <chris@disavowed.jp>
Reported-by: Doug Brown <doug@downtowndougbrown.com>
Signed-off-by: Vincent Duvert <vincent.ldev@duvert.net>
[lukas: add missing tags]
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Cc: stable@vger.kernel.org # v5.1+
Cc: Yue Haibing <yuehaibing@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/appletalk/atalk_proc.c

@@ -229,6 +229,8 @@ int __init atalk_proc_init(void)
 				     sizeof(struct aarp_iter_state), NULL))
 		goto out;
 
+	return 0;
+
 out:
 	remove_proc_subtree("atalk", init_net.proc_net);
 	return -ENOMEM;