Fix buildbot test failures on debug and gcstress host.

This CL moves test expectations from EXEC_FAILED group to ERROR so
buildbot correctly interprets failing tests.

Bug: 234324321
Test: art/tools/run-libcore-tests.sh --mode=host --variant=X64 \
      --debug --gcstress
Change-Id: I33b5c598bf6a20c6188407beaea3c255e7020a59
1 file changed