Revert "f2fs: fix to clean previous mount option when remount_fs"

Don't clear old mount option before parse new option during ->remount_fs
like other generic filesystems.

This reverts commit 26666c8a4366debae30ae37d0688b2bec92d196a.

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

fs/f2fs/super.c

@@ -846,7 +846,6 @@ static int f2fs_remount(struct super_block *sb, int *flags, char *data)
 			clear_sbi_flag(sbi, SBI_NEED_SB_WRITE);
 	}
 
-	sbi->mount_opt.opt = 0;
 	default_options(sbi);
 
 	/* parse mount options */