Move the validation before the tests, since it's completely agnostic.
Any empty lines have already been stripped away.
This effectively removes fairly confusing output such as:
Running unreliable deqp-gl32 on vtest-softpipe: Fail - passed 0/0 tests
It used to happen since we run piglit/deqp with empty list, when we did
not need to run it at all.
Aside: this has uncovered a piglit bug, where it will run all tests,
when the list is empty.
Signed-off-by: Emil Velikov <emil.velikov@collabora.com>
Reviewed-by: Elie Tournier <elie.tournier@collabora.com>