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/adfs/inode.c b/fs/adfs/inode.c
index d5250c5..1dab6a1 100644
--- a/fs/adfs/inode.c
+++ b/fs/adfs/inode.c
@@ -247,7 +247,7 @@
 	inode->i_gid	 = ADFS_SB(sb)->s_gid;
 	inode->i_ino	 = obj->file_id;
 	inode->i_size	 = obj->size;
-	inode->i_nlink	 = 2;
+	set_nlink(inode, 2);
 	inode->i_blocks	 = (inode->i_size + sb->s_blocksize - 1) >>
 			    sb->s_blocksize_bits;