f2fs: introduce f2fs_i_size_write with mark_inode_dirty_sync

This patch introduces f2fs_i_size_write() to call mark_inode_dirty_sync() with
i_size_write().

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
index 160b15b..d832bf4 100644
--- a/fs/f2fs/super.c
+++ b/fs/f2fs/super.c
@@ -568,7 +568,7 @@
 			f2fs_destroy_extent_node(inode);
 
 			sb_start_intwrite(inode->i_sb);
-			i_size_write(inode, 0);
+			f2fs_i_size_write(inode, 0);
 
 			if (F2FS_HAS_BLOCKS(inode))
 				f2fs_truncate(inode, true);