ext4: fix flags validity checking for EXT4_IOC_CHECKPOINT

Use the correct bitmask when checking for any not-yet-supported flags.

Link: https://lore.kernel.org/r/20210702173425.1276158-1-tytso@mit.edu
Fixes: 351a0a3f ("ext4: add ioctl EXT4_IOC_CHECKPOINT")
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Leah Rumancik <leah.rumancik@gmail.com>

fs/ext4/ioctl.c

@@ -823,7 +823,7 @@ static int ext4_ioctl_checkpoint(struct file *filp, unsigned long arg)
 	if (!EXT4_SB(sb)->s_journal)
 		return -ENODEV;
 
-	if (flags & ~JBD2_JOURNAL_FLUSH_VALID)
+	if (flags & ~EXT4_IOC_CHECKPOINT_FLAG_VALID)
 		return -EINVAL;
 
 	q = bdev_get_queue(EXT4_SB(sb)->s_journal->j_dev);