tests/unittests: report results to the environment on native

tests/unittests/Makefile

@@ -35,6 +35,7 @@ INCLUDES += -I$(RIOTBASE)/tests/unittests/common
 
 # some tests need more stack
 CFLAGS += -DTHREAD_STACKSIZE_MAIN=THREAD_STACKSIZE_LARGE
+CFLAGS += -DCONFIG_CORE_EXIT_WITH_MAIN=1
 
 # for these boards, enable asan (Address Sanitizer)
 ASAN_BOARDS ?= native native64

tests/unittests/main.c

@@ -49,7 +49,5 @@ int main(void)
 #ifndef NO_TEST_SUITES
     UNCURRY(RUN_TEST_SUITES, TEST_SUITES)
 #endif
-    TESTS_END();
-
-    return 0;
+    return TESTS_END();
 }