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/ext2/inode.c b/fs/ext2/inode.c
index a8a58f6..91a6945 100644
--- a/fs/ext2/inode.c
+++ b/fs/ext2/inode.c
@@ -1321,7 +1321,7 @@
 		inode->i_uid |= le16_to_cpu(raw_inode->i_uid_high) << 16;
 		inode->i_gid |= le16_to_cpu(raw_inode->i_gid_high) << 16;
 	}
-	inode->i_nlink = le16_to_cpu(raw_inode->i_links_count);
+	set_nlink(inode, le16_to_cpu(raw_inode->i_links_count));
 	inode->i_size = le32_to_cpu(raw_inode->i_size);
 	inode->i_atime.tv_sec = (signed)le32_to_cpu(raw_inode->i_atime);
 	inode->i_ctime.tv_sec = (signed)le32_to_cpu(raw_inode->i_ctime);