IB/mad cleanup: Generalize processing of MAD data

ib_find_send_mad only needs access to the MAD header not the full IB MAD.
Change the local variable to ib_mad_hdr and change the corresponding cast.

This allows for clean usage of this function with both IB and OPA MADs because
OPA MADs carry the same header as IB MADs.
Signed-off-by: NIra Weiny <ira.weiny@intel.com>
Signed-off-by: NDoug Ledford <dledford@redhat.com>

drivers/infiniband/core/mad.c

@@ -1815,18 +1815,18 @@ ib_find_send_mad(const struct ib_mad_agent_private *mad_agent_priv,
 		 const struct ib_mad_recv_wc *wc)
 {
 	struct ib_mad_send_wr_private *wr;
-	struct ib_mad *mad;
+	const struct ib_mad_hdr *mad_hdr;
 
-	mad = (struct ib_mad *)wc->recv_buf.mad;
+	mad_hdr = &wc->recv_buf.mad->mad_hdr;
 
 	list_for_each_entry(wr, &mad_agent_priv->wait_list, agent_list) {
-		if ((wr->tid == mad->mad_hdr.tid) &&
+		if ((wr->tid == mad_hdr->tid) &&
 		    rcv_has_same_class(wr, wc) &&
 		    /*
 		     * Don't check GID for direct routed MADs.
 		     * These might have permissive LIDs.
 		     */
-		    (is_direct(wc->recv_buf.mad->mad_hdr.mgmt_class) ||
+		    (is_direct(mad_hdr->mgmt_class) ||
 		     rcv_has_same_gid(mad_agent_priv, wr, wc)))
 			return (wr->status == IB_WC_SUCCESS) ? wr : NULL;
 	}
@@ -1837,14 +1837,14 @@ ib_find_send_mad(const struct ib_mad_agent_private *mad_agent_priv,
 	 */
 	list_for_each_entry(wr, &mad_agent_priv->send_list, agent_list) {
 		if (is_rmpp_data_mad(mad_agent_priv, wr->send_buf.mad) &&
-		    wr->tid == mad->mad_hdr.tid &&
+		    wr->tid == mad_hdr->tid &&
 		    wr->timeout &&
 		    rcv_has_same_class(wr, wc) &&
 		    /*
 		     * Don't check GID for direct routed MADs.
 		     * These might have permissive LIDs.
 		     */
-		    (is_direct(wc->recv_buf.mad->mad_hdr.mgmt_class) ||
+		    (is_direct(mad_hdr->mgmt_class) ||
 		     rcv_has_same_gid(mad_agent_priv, wr, wc)))
 			/* Verify request has not been canceled */
 			return (wr->status == IB_WC_SUCCESS) ? wr : NULL;