Raspberry: Fixed crash if memory allocation for cursor failed.

src/video/raspberry/SDL_rpimouse.c

@@ -70,7 +70,16 @@ RPI_CreateCursor(SDL_Surface * surface, int hot_x, int hot_y)
     SDL_assert(surface->pitch == surface->w * 4);
     
     cursor = (SDL_Cursor *) SDL_calloc(1, sizeof(*cursor));
+    if (cursor == NULL) {
+        SDL_OutOfMemory();
+        return NULL;
+    }
     curdata = (RPI_CursorData *) SDL_calloc(1, sizeof(*curdata));
+    if (curdata == NULL) {
+        SDL_OutOfMemory();
+        SDL_free(cursor);
+        return NULL;
+    }
 
     curdata->hot_x = hot_x;
     curdata->hot_y = hot_y;