Simplify header

include/starpu_driver.h

@@ -57,8 +57,6 @@ struct starpu_driver
 		unsigned cuda_id;
 #if defined(STARPU_USE_OPENCL) && !defined(__CUDACC__)
 		cl_device_id opencl_id;
-#else
-		unsigned opencl_id;
 #endif
 	} id;
 };

src/core/workers.c

@@ -643,10 +643,12 @@ static unsigned _starpu_may_launch_driver(struct starpu_conf *conf,
 			if (d->id.cuda_id == conf->not_launched_drivers[i].id.cuda_id)
 				return 0;
 			break;
+#ifdef STARPU_USE_OPENCL
 		case STARPU_OPENCL_WORKER:
 			if (d->id.opencl_id == conf->not_launched_drivers[i].id.opencl_id)
 				return 0;
 			break;
+#endif
 		default:
 			STARPU_ABORT();
 		}