kms_frontbuffer_tracking: remove duplicated pairs on multidraw
kms_frontbuffer_tracking: remove duplicated pairs on multidraw

If we already tested the combination of m1+m2, don't test m2+m1 later:
the drawing pattern used already has 4 squares, so we're already
testing the "m2 followed by m1" case.

This should reduce the test time from about 60s to about 30s.

Signed-off-by: Paulo Zanoni <cc0e04a2103c45cd195651d976f79813d0f66bdf@intel.com>

chenxianqin/intel-gpu-tools,chenxianqin/intel-gpu-tools,tiagovignatti/intel-gpu-tools,mv0/intel-gpu-tools,chenxianqin/intel-gpu-tools,tiagovignatti/intel-gpu-tools,tiagovignatti/intel-gpu-tools,tiagovignatti/intel-gpu-tools,mv0/intel-gpu-tools,mv0/intel-gpu-tools,mv0/intel-gpu-tools,chenxianqin/intel-gpu-tools