freedreno: defer flush_queue allocation

Some apps, like warsow, create a bazillion contexts but don't render on
most of them.

Signed-off-by: Rob Clark <robdclark@gmail.com>

src/gallium/drivers/freedreno/freedreno_batch.c

@@ -265,6 +265,10 @@ batch_flush(struct fd_batch *batch)
 	if (batch->ctx->screen->reorder) {
 		struct fd_batch *tmp = NULL;
 		fd_batch_reference(&tmp, batch);
+
+		if (!util_queue_is_initialized(&batch->ctx->flush_queue))
+			util_queue_init(&batch->ctx->flush_queue, "flush_queue", 16, 1);
+
 		util_queue_add_job(&batch->ctx->flush_queue,
 				batch, &batch->flush_fence,
 				batch_flush_func, batch_cleanup_func);

src/gallium/drivers/freedreno/freedreno_context.c

@@ -184,8 +184,6 @@ fd_context_init(struct fd_context *ctx, struct pipe_screen *pscreen,
 	 */
 	if (!screen->reorder) {
 		ctx->batch = fd_bc_alloc_batch(&screen->batch_cache, ctx);
-	} else {
-		util_queue_init(&ctx->flush_queue, "flush_queue", 16, 1);
 	}
 
 	util_slab_create(&ctx->transfer_pool, sizeof(struct fd_transfer),