common/rc: fix xfs_io scrub command existence test

The name of the xfs_io scrub subcommand to test for the existence of
the ioctl has been changed to 'test' from 'dummy', so fix xfstests.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Eryu Guan <eguan@redhat.com>
Signed-off-by: Eryu Guan <eguan@redhat.com>
1 file changed