Pointer as bool (libsdl-org#7214)

test/testrwlock.c

@@ -67,7 +67,7 @@ int main(int argc, char *argv[])
 
     /* Initialize test framework */
     state = SDLTest_CommonCreateState(argv, 0);
-    if (state == NULL) {
+    if (!state) {
         return 1;
     }
 
@@ -141,7 +141,7 @@ int main(int argc, char *argv[])
     SDL_AtomicSet(&doterminate, 0);
 
     rwlock = SDL_CreateRWLock();
-    if (rwlock == NULL) {
+    if (!rwlock) {
         SDL_LogError(SDL_LOG_CATEGORY_APPLICATION, "Couldn't create rwlock: %s\n", SDL_GetError());
         SDL_Quit();
         SDLTest_CommonDestroyState(state);