[HIP] Increase blender perf diff threshold (#294)

This parameter sets how much difference in runtime the blender workloads
are allowed to show when run in the testing.
In reality it was advised to set this to 15% instead of the 5% shown
here.

With this patch, we increase the default threshold to 10% to see if this
gives us enough wiggle room out of the box to not see any runtime
related flakiness.

Author: jplehr

External/HIP/workload/blender/test_blender.sh.in

@@ -1,7 +1,7 @@
 #!/bin/bash
 
 TEST_SUITE_HIP_ROOT=${TEST_SUITE_HIP_ROOT:-"@TEST_SUITE_HIP_ROOT@"}
-perf_thresh=${HIP_BLENDER_TEST_PERF_THRESH:-5}
+perf_thresh=${HIP_BLENDER_TEST_PERF_THRESH:-10}
 
 export CCC_OVERRIDE_OPTIONS=${HIP_BLENDER_TEST_CCC_OVERRIDE_OPTIONS:-"+-v"}