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/ubifs/xattr.c b/fs/ubifs/xattr.c
index 993adc8..bf18f7a 100644
--- a/fs/ubifs/xattr.c
+++ b/fs/ubifs/xattr.c
@@ -561,7 +561,7 @@
 	clear_nlink(inode);
 	err = remove_xattr(c, host, inode, &nm);
 	if (err)
-		inode->i_nlink = 1;
+		set_nlink(inode, 1);
 
 	/* If @i_nlink is 0, 'iput()' will delete the inode */
 	iput(inode);