openpower-pels: Check response header

Using the new PLDM API requires checking the response header for the
request and datagram flags, as those indicate that the message isn't
really a response.

Change-Id: I38f8e77bd5defaf611695649bb75d589b2548f17
Signed-off-by: Eddie James <eajames@linux.ibm.com>
diff --git a/extensions/openpower-pels/pldm_interface.cpp b/extensions/openpower-pels/pldm_interface.cpp
index 392bd00..c8f59e2 100644
--- a/extensions/openpower-pels/pldm_interface.cpp
+++ b/extensions/openpower-pels/pldm_interface.cpp
@@ -275,6 +275,7 @@
     pldm_tid_t pldmTID;
     auto rc = pldm_transport_recv_msg(transport, &pldmTID, &responseMsg,
                                       &responseSize);
+    struct pldm_msg_hdr* hdr = (struct pldm_msg_hdr*)responseMsg;
     if (pldmTID != _eid)
     {
         // We got a response to someone else's message. Ignore it.
@@ -298,6 +299,11 @@
 
         responseMsg = nullptr;
     }
+    if (hdr && (hdr->request || hdr->datagram))
+    {
+        free(responseMsg);
+        return;
+    }
 
     cleanupCmd();