f2fs: fix time update in case of f2fs fallocate

After doing a punch hole or expanding inode doing fallocation.
The change and modification time are not update for the file.
So, update time after no issue is observed in fallocate.
Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>
Signed-off-by: Amit Sahrawat <a.sahrawat@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

fs/f2fs/file.c

@@ -545,6 +545,11 @@ static long f2fs_fallocate(struct file *file, int mode,
 	else
 		ret = expand_inode_data(inode, offset, len, mode);
 
+	if (!ret) {
+		inode->i_mtime = inode->i_ctime = CURRENT_TIME;
+		mark_inode_dirty(inode);
+	}
+
 	f2fs_balance_fs(sbi);
 	return ret;
 }