nilfs2: replace nilfs_warning() with nilfs_msg()

Use nilfs_msg() to output warning messages and get rid of
nilfs_warning() function.  This also removes function names from the
messages unless we embed them explicitly in format strings.  Instead,
some messages are revised to clarify the context.

[arnd@arndb.de: avoid warning about unused variables]
  Link: http://lkml.kernel.org/r/20160615201945.3348205-1-arnd@arndb.de
Link: http://lkml.kernel.org/r/1464875891-5443-6-git-send-email-konishi.ryusuke@lab.ntt.co.jp
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/fs/nilfs2/namei.c b/fs/nilfs2/namei.c
index 1ec8ae5..dbcf1dc 100644
--- a/fs/nilfs2/namei.c
+++ b/fs/nilfs2/namei.c
@@ -283,9 +283,9 @@
 		goto out;
 
 	if (!inode->i_nlink) {
-		nilfs_warning(inode->i_sb, __func__,
-			      "deleting nonexistent file (%lu), %d",
-			      inode->i_ino, inode->i_nlink);
+		nilfs_msg(inode->i_sb, KERN_WARNING,
+			  "deleting nonexistent file (ino=%lu), %d",
+			  inode->i_ino, inode->i_nlink);
 		set_nlink(inode, 1);
 	}
 	err = nilfs_delete_entry(de, page);