win-capture: Fix potentially uninitialized vars

plugins/win-capture/duplicator-monitor-capture.c

@@ -203,20 +203,18 @@ static void duplicator_capture_render(void *data, gs_effect_t *effect)
 		gs_enable_color(true, true, true, false);
 
 		if (rot != 0) {
-			float x;
-			float y;
+			float x = 0.0f;
+			float y = 0.0f;
 
 			switch (rot) {
 			case 90:
 				x = (float)capture->height;
-				y = 0.0f;
 				break;
 			case 180:
 				x = (float)capture->width;
 				y = (float)capture->height;
 				break;
 			case 270:
-				x = 0.0f;
 				y = (float)capture->width;
 				break;
 			}