fix push_crc VDP_bytes to wrong request context

in this context, req is the unpender, but we need to push to the crc
node's parent

src/vdp_pesi.c

@@ -1706,6 +1706,7 @@ push_crc(struct req *req, struct bytes_tree *tree,
 
 	assert(node->type == T_CRC);
 
+	(void) req;
 	(void) tree;
 
 	nex = node->parent;
@@ -1732,7 +1733,8 @@ push_crc(struct req *req, struct bytes_tree *tree,
 			parent_gzip->l_crc += nex->nexus.gzip.l_crc;
 		} else {
 			gzip_tailbuf(tailbuf, &nex->nexus.gzip);
-			return (VDP_bytes(req, VDP_FLUSH, tailbuf, sizeof(tailbuf)));
+			return (VDP_bytes(nex->nexus.req,
+			    VDP_FLUSH, tailbuf, sizeof(tailbuf)));
 		}
 		break;
 	default: