test/malloc: fix missing free

[ upstream commit ec8ef136b8d9340003118bb25390d7c6989178bf ]

Free the allocated buffer before returning.

Fixes: a40a1f8 ("app: various tests update")

Signed-off-by: Ruifeng Wang <ruifeng.wang@arm.com>
Reviewed-by: Feifei Wang <feifei.wang2@arm.com>
Acked-by: Anatoly Burakov <anatoly.burakov@intel.com>

app/test/test_malloc.c

@@ -927,6 +927,7 @@ test_alloc_single_socket(int32_t socket)
 	if (mem == NULL)
 		return -1;
 	if (addr_to_socket(mem) != desired_socket) {
+		rte_free(mem);
 		return -1;
 	}
 	rte_free(mem);