Removed SDL_bool in favor of plain bool

We require stdbool.h in the build environment, so we might as well use the plain bool type.

If your environment doesn't have stdbool.h, this simple replacement will suffice:
typedef signed char bool;

test/testhotplug.c

@@ -26,9 +26,9 @@ int main(int argc, char *argv[])
     SDL_Joystick *joystick = NULL;
     SDL_Haptic *haptic = NULL;
     SDL_JoystickID instance = 0;
-    SDL_bool keepGoing = SDL_TRUE;
+    bool keepGoing = true;
     int i;
-    SDL_bool enable_haptic = SDL_TRUE;
+    bool enable_haptic = true;
     Uint32 init_subsystems = SDL_INIT_VIDEO | SDL_INIT_JOYSTICK;
     SDLTest_CommonState *state;
 
@@ -45,7 +45,7 @@ int main(int argc, char *argv[])
         consumed = SDLTest_CommonArg(state, i);
         if (!consumed) {
             if (SDL_strcasecmp(argv[i], "--nohaptic") == 0) {
-                enable_haptic = SDL_FALSE;
+                enable_haptic = false;
                 consumed = 1;
             }
         }
@@ -94,7 +94,7 @@ int main(int argc, char *argv[])
         while (SDL_PollEvent(&event)) {
             switch (event.type) {
             case SDL_EVENT_QUIT:
-                keepGoing = SDL_FALSE;
+                keepGoing = false;
                 break;
             case SDL_EVENT_KEYBOARD_ADDED:
                 SDL_Log("Keyboard '%s' added  : %" SDL_PRIu32 "\n", SDL_GetKeyboardNameForID(event.kdevice.which), event.kdevice.which);
@@ -163,7 +163,7 @@ int main(int argc, char *argv[])
                 }
                 if (event.jbutton.button == 0) {
                     SDL_Log("Exiting due to button press of button 0\n");
-                    keepGoing = SDL_FALSE;
+                    keepGoing = false;
                 }
                 break;
             case SDL_EVENT_JOYSTICK_BUTTON_UP: