dev: Warn when resp packet is error in dma port

This CL adds a warning when the response packet is error.

Change-Id: I8e94dc2b85cd1753a4d6265cfda3cd5d6325f425
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/71778
Reviewed-by: Jason Lowe-Power <power.jg@gmail.com>
Maintainer: Jason Lowe-Power <power.jg@gmail.com>
Reviewed-by: Yu-hsin Wang <yuhsingw@google.com>
Tested-by: kokoro <noreply+kokoro@google.com>

src/dev/dma_device.cc

@@ -68,6 +68,7 @@ DmaPort::handleRespPacket(PacketPtr pkt, Tick delay)
 {
     // Should always see a response with a sender state.
     assert(pkt->isResponse());
+    warn_if(pkt->isError(), "Response pkt error.");
 
     // Get the DMA sender state.
     auto *state = dynamic_cast<DmaReqState*>(pkt->senderState);