scripts/run-tests.sh: use single combined test list
scripts/run-tests.sh: use single combined test list

i-g-t now creates a single combined test list for tests with
and without subtests. This patch adapts run-tests.sh to that
change.

Signed-off-by: Mike Mason <547fc8589da6e3420741b48c2fd4308f78467919@intel.com>
Signed-off-by: Thomas Wood <b9025d6a953b68f894a0f6a80fd2af6d55b0badd@intel.com>

mv0/intel-gpu-tools,chenxianqin/intel-gpu-tools,dlespiau/checkmate-test-igt,tiagovignatti/intel-gpu-tools,chenxianqin/intel-gpu-tools,chenxianqin/intel-gpu-tools,mv0/intel-gpu-tools,dlespiau/checkmate-test-igt,tiagovignatti/intel-gpu-tools,tiagovignatti/intel-gpu-tools,dlespiau/checkmate-test-igt,chenxianqin/intel-gpu-tools,tiagovignatti/intel-gpu-tools,mv0/intel-gpu-tools,dlespiau/checkmate-test-igt,mv0/intel-gpu-tools