give proper prototypes

test/malloc/malloc-standard-alignment.c

@@ -23,7 +23,7 @@ struct llist_s {
 	struct llist_s *link;
 } *phead;
 
-int main()
+int main(int argc, char *argv[])
 {
 	char *line, *reg;
 

test/malloc/realloc-can-shrink.c

@@ -4,7 +4,7 @@
 
 #define LARGE_BUFFER (1 << 20) /* idea is to span a lot of pages */
 
-int main()
+int main(int argc, char *argv[])
 {
 	int count = 20;
 	char *ptr = NULL;