Pointer as bool (libsdl-org#7214)

test/testpopup.c

@@ -194,7 +194,7 @@ static void loop(void)
 
     /* Show the tooltip if the delay period has elapsed */
     if (SDL_GetTicks() > tooltip_timer) {
-        if (tooltip.win == NULL) {
+        if (!tooltip.win) {
             create_popup(&tooltip, SDL_FALSE);
         }
     }
@@ -244,7 +244,7 @@ int main(int argc, char *argv[])
 
     /* Initialize test framework */
     state = SDLTest_CommonCreateState(argv, SDL_INIT_VIDEO);
-    if (state == NULL) {
+    if (!state) {
         return 1;
     }