Fix regression in intorel_receive.

Commit fa287d01 missed retaining the original
negation for `is_bulkload` argument to `heap_insert()`. So, in case bulkload
being false, the use_wal also became false and no xlog records were getting
generated. Commit b8f8fccc attempted to fix it
but just didn't fix the nagation at right place.

src/backend/executor/execMain.c

@@ -5208,7 +5208,7 @@ intorel_receive(TupleTableSlot *slot, DestReceiver *self)
 		heap_insert(into_rel,
 					tuple,
 					myState->estate->es_output_cid,
-					myState->is_bulkload,
+					!myState->is_bulkload,
 					false, /* never any point in using FSM */
 					GetCurrentTransactionId());