executor: terminate on corrupted coverage
executor: terminate on corrupted coverage

New measures still does not help against fuzzer producing
fake corrupted coverage.
Try to terminate instantly as we detect bad coverage.

google/syzkaller,xairy/syzkaller,google/syzkaller,google/syzkaller,xairy/syzkaller,xairy/syzkaller,xairy/syzkaller,google/syzkaller,google/syzkaller,xairy/syzkaller,google/syzkaller,xairy/syzkaller,xairy/syzkaller,google/syzkaller