Test malloc, set unused to NULL if it fails

---

 tests/heapshrink-helper.c |    4 +++-

 1 file changed, 3 insertions(+), 1 deletion(-)

--- a/tests/heapshrink-helper.c

+++ b/tests/heapshrink-helper.c

@@ -21,5 +21,7 @@

 static void __attribute__((constructor)) setup_heapshrink_helper(void)

 {

-	(void) malloc(1);

+	void *unused = malloc(1);

+	if (unused)

+		unused = NULL;

 }