Fixed HIDAPI hotplug detection when initializing gamepads off the main thread

src/hidapi/SDL_hidapi.c

@@ -388,7 +388,9 @@ static void HIDAPI_UpdateDiscovery(void)
     }
 
 #if defined(SDL_PLATFORM_WIN32) || defined(SDL_PLATFORM_WINGDK)
-#if 0 // just let the usual SDL_PumpEvents loop dispatch these, fixing bug 4286. --ryan.
+    if (SDL_IsMainThread()) {
+        // just let the usual SDL_PumpEvents loop dispatch these, fixing bug 2998. --ryan.
+    } else {
         // We'll only get messages on the same thread that created the window
         if (SDL_GetCurrentThreadID() == SDL_HIDAPI_discovery.m_nThreadID) {
             MSG msg;
@@ -399,7 +401,7 @@ static void HIDAPI_UpdateDiscovery(void)
                 }
             }
         }
-#endif
+    }
 #endif // defined(SDL_PLATFORM_WIN32) || defined(SDL_PLATFORM_WINGDK)
 
 #ifdef SDL_PLATFORM_MACOS