filesystems: add set_nlink()

Replace remaining direct i_nlink updates with a new set_nlink()
updater function.

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Tested-by: Toshiyuki Okajima <toshi.okajima@jp.fujitsu.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
diff --git a/fs/nilfs2/namei.c b/fs/nilfs2/namei.c
index a314199..768982d 100644
--- a/fs/nilfs2/namei.c
+++ b/fs/nilfs2/namei.c
@@ -289,7 +289,7 @@
 		nilfs_warning(inode->i_sb, __func__,
 			      "deleting nonexistent file (%lu), %d\n",
 			      inode->i_ino, inode->i_nlink);
-		inode->i_nlink = 1;
+		set_nlink(inode, 1);
 	}
 	err = nilfs_delete_entry(de, page);
 	if (err)