Fix wrong asserting in binary cdo selector parsing

Binary operations failed on buggz assertion, rather than running into
'unimplemented' code section that needs fixing.

maestro/pool.c

@@ -1369,7 +1369,8 @@ mstro__csq_validate(struct mstro_csq_val *csq,
     case MSTRO_CSQ_OP_EQ:  /* fallthrough */
     case MSTRO_CSQ_OP_NEQ: {
       /* translate lhs wrt. schema, rhs wrt. lhs type */
-      assert(csq->has.key!=NULL);
+      assert(csq->kv_op.lhs!=NULL);
+      assert(csq->kv_op.rhs!=NULL);
       mstro_schema_attribute attr=NULL;
       char *tmp=NULL;
       mstro_status s = mstro__csq_lookup(schema, namespace,