Update core_input_gamepad.c (#2903)

examples/core/core_input_gamepad.c

@@ -174,7 +174,7 @@ int main(void)
                     DrawText(TextFormat("AXIS %i: %.02f", i, GetGamepadAxisMovement(0, i)), 20, 70 + 20*i, 10, DARKGRAY);
                 }
 
-                if (GetGamepadButtonPressed() != -1) DrawText(TextFormat("DETECTED BUTTON: %i", GetGamepadButtonPressed()), 10, 430, 10, RED);
+                if (GetGamepadButtonPressed() != GAMEPAD_BUTTON_UNKNOWN) DrawText(TextFormat("DETECTED BUTTON: %i", GetGamepadButtonPressed()), 10, 430, 10, RED);
                 else DrawText("DETECTED BUTTON: NONE", 10, 430, 10, GRAY);
             }
             else