wasapi: fix memory leak on unlikely failure case.

Author: icculus

src/core/windows/SDL_immdevice.c

@@ -173,10 +173,16 @@ static SDL_AudioDevice *SDL_IMMDevice_Add(const bool recording, const char *devn
                 return NULL;
             }
 
-            SDL_memcpy(&recording_handle->directsound_guid, dsoundguid, sizeof(GUID));
             recording_handle->immdevice_id = SDL_wcsdup(devid);
+            if (!recording_handle->immdevice_id) {
+                SDL_free(recording_handle);
+                return NULL;
+            }
+
+            SDL_copyp(&recording_handle->directsound_guid, &dsoundguid);
 
-            if (!recording_handle->immdevice_id || !SDL_AddAudioDevice(true, devname, &spec, recording_handle)) {
+            if (!SDL_AddAudioDevice(true, devname, &spec, recording_handle)) {
+                SDL_free(recording_handle->immdevice_id);
                 SDL_free(recording_handle);
             }
         }