Fix db_crashtest.py call inconsistency in crash_test.mk (#9935)

Summary:
Some tests crashing because not using custom DB_STRESS_CMD

Pull Request resolved: https://github.com/facebook/rocksdb/pull/9935

Test Plan: internal tests

Reviewed By: riversand963

Differential Revision: D36104347

Pulled By: pdillinger

fbshipit-source-id: 23f080704a124174203f54ffd85578c2047effe5

crash_test.mk

@@ -65,10 +65,10 @@ blackbox_crash_test_with_ts: $(DB_STRESS_CMD)
 	$(CRASHTEST_PY) --enable_ts blackbox $(CRASH_TEST_EXT_ARGS)
 
 blackbox_crash_test_with_multiops_wc_txn: $(DB_STRESS_CMD)
-	$(PYTHON) -u tools/db_crashtest.py --test_multiops_txn --write_policy write_committed blackbox $(CRASH_TEST_EXT_ARGS)
+	$(CRASHTEST_PY) --test_multiops_txn --write_policy write_committed blackbox $(CRASH_TEST_EXT_ARGS)
 
 blackbox_crash_test_with_multiops_wp_txn: $(DB_STRESS_CMD)
-	$(PYTHON) -u tools/db_crashtest.py --test_multiops_txn --write_policy write_prepared blackbox $(CRASH_TEST_EXT_ARGS)
+	$(CRASHTEST_PY) --test_multiops_txn --write_policy write_prepared blackbox $(CRASH_TEST_EXT_ARGS)
 
 ifeq ($(CRASH_TEST_KILL_ODD),)
   CRASH_TEST_KILL_ODD=888887