use int main(void) for main, so clang won't complain about unused argc/argv

circular-buffer.c

@@ -91,7 +91,7 @@ bool cb_read(cb_t * cb, elem_t * elem) {
 
 /* Test it. */
 
-int main(int argc, char *argv[]) {
+int main(void) {
   /* Initialize empty CB_SIZE-element circular buffer. */
   cb_t *test_cb = malloc(sizeof(cb_t));
   if (!test_cb)

linked-list.c

@@ -122,7 +122,7 @@ list_node_t* list_elementat(list_t *list, int i) {
   return cur;
 }
 
-int main(int argc, char *argv[]) {
+int main(void) {
 
   /* Test empty list */
   list_t *emptylist = malloc(sizeof(list_t));

mandelbrot.c

@@ -64,7 +64,7 @@ void drawmandelbrot(SDL_Surface * surface) {
   }
 }
 
-int main(int argc, char *argv[]) {
+int main(void) {
   /* Set up SDL. */
   if (SDL_Init(SDL_INIT_EVERYTHING) < 0) {
     fprintf(stderr, "Error: Could not initialize SDL: %s.\n",