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/fat/inode.c b/fs/fat/inode.c
index 1726d73..808cac7 100644
--- a/fs/fat/inode.c
+++ b/fs/fat/inode.c
@@ -379,7 +379,7 @@
 			return error;
 		MSDOS_I(inode)->mmu_private = inode->i_size;
 
-		inode->i_nlink = fat_subdirs(inode);
+		set_nlink(inode, fat_subdirs(inode));
 	} else { /* not a directory */
 		inode->i_generation |= 1;
 		inode->i_mode = fat_make_mode(sbi, de->attr,
@@ -1233,7 +1233,7 @@
 	fat_save_attrs(inode, ATTR_DIR);
 	inode->i_mtime.tv_sec = inode->i_atime.tv_sec = inode->i_ctime.tv_sec = 0;
 	inode->i_mtime.tv_nsec = inode->i_atime.tv_nsec = inode->i_ctime.tv_nsec = 0;
-	inode->i_nlink = fat_subdirs(inode)+2;
+	set_nlink(inode, fat_subdirs(inode)+2);
 
 	return 0;
 }