radeonsi: handle index buffer alloc failures

Cc: 11.0 <mesa-stable@lists.freedesktop.org>
Acked-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Michel Dänzer <michel.daenzer@amd.com>

src/gallium/drivers/radeonsi/si_state_draw.c

@@ -782,6 +782,10 @@ void si_draw_vbo(struct pipe_context *ctx, const struct pipe_draw_info *info)
 
 			u_upload_alloc(sctx->b.uploader, start_offset, count * 2,
 				       &out_offset, &out_buffer, &ptr);
+			if (!out_buffer) {
+				pipe_resource_reference(&ib.buffer, NULL);
+				return;
+			}
 
 			util_shorten_ubyte_elts_to_userptr(&sctx->b.b, &ib, 0,
 							   ib.offset + start_offset,
@@ -802,6 +806,8 @@ void si_draw_vbo(struct pipe_context *ctx, const struct pipe_draw_info *info)
 			u_upload_data(sctx->b.uploader, start_offset, count * ib.index_size,
 				      (char*)ib.user_buffer + start_offset,
 				      &ib.offset, &ib.buffer);
+			if (!ib.buffer)
+				return;
 			/* info->start will be added by the drawing code */
 			ib.offset -= start_offset;
 		}