Fix parallel test sometimes doesn't fail with failed tests. (#7147)

Summary:
In CircleCI tests, we failed to fail tests properly if parallel doesn't return an error code. It's probably would happen when unit tests fail with signals, rather than return values. Fix them.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/7147

Test Plan: Manually ingest a failure and see it to fail.

Reviewed By: jay-zhuang

Differential Revision: D22611594

fbshipit-source-id: 88a42425a41d1213d29bd2e7c80731d2bdd5644b

Makefile

@@ -853,7 +853,8 @@ check_0:
 	  | build_tools/gnu_parallel -j$(J) --plain --joblog=LOG $$eta --gnu  $(parallel_com) ; \
 	parallel_retcode=$$? ; \
 	awk '{ if ($$7 != 0 || $$8 != 0) { if ($$7 == "Exitval") { h = $$0; } else { if (!f) print h; print; f = 1 } } } END { if(f) exit 1; }' < LOG ; \
-	if [ $$parallel_retcode -ne 0 ] ; then exit 1 ; fi
+	awk_retcode=$$?; \
+	if [ $$parallel_retcode -ne 0 ] || [ $$awk_retcode -ne 0 ] ; then exit 1 ; fi
 
 valgrind-exclude-regexp = InlineSkipTest.ConcurrentInsert|TransactionStressTest.DeadlockStress|DBCompactionTest.SuggestCompactRangeNoTwoLevel0Compactions|BackupableDBTest.RateLimiting|DBTest.CloseSpeedup|DBTest.ThreadStatusFlush|DBTest.RateLimitingTest|DBTest.EncodeDecompressedBlockSizeTest|FaultInjectionTest.UninstalledCompaction|HarnessTest.Randomized|ExternalSSTFileTest.CompactDuringAddFileRandom|ExternalSSTFileTest.IngestFileWithGlobalSeqnoRandomized|MySQLStyleTransactionTest.TransactionStressTest