Make utils/create_reference_dumps.py slightly less slower when -l is specified.

Bug: 64267858

Test: Without this change:
          rm -rf $ANDROID_BUILD_TOP/out; utils/create_reference_dumps.py
	  -l libjpeg -> > 30 minutes
      With this change:
          rm -rf $ANDROID_BUILD_TOP/out; utils/create_reference_dumps.py
	  -l libjpeg -> approx 11.5 minutes

Change-Id: I9c145ed5d8c9a9cc2cb1dc7db9ab9b83843a291e
2 files changed