iw_cxgb4: set *bad_wr for post_send/post_recv errors

There are a few cases in c4iw_post_send() and c4iw_post_receive()
where *bad_wr is not set when an error is returned.  This can
cause a crash if the application tries to use bad_wr.
Signed-off-by: Steve Wise <swise@opengridcomputing.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

drivers/infiniband/hw/cxgb4/qp.c

@@ -797,11 +797,13 @@ int c4iw_post_send(struct ib_qp *ibqp, struct ib_send_wr *wr,
 	spin_lock_irqsave(&qhp->lock, flag);
 	if (t4_wq_in_error(&qhp->wq)) {
 		spin_unlock_irqrestore(&qhp->lock, flag);
+		*bad_wr = wr;
 		return -EINVAL;
 	}
 	num_wrs = t4_sq_avail(&qhp->wq);
 	if (num_wrs == 0) {
 		spin_unlock_irqrestore(&qhp->lock, flag);
+		*bad_wr = wr;
 		return -ENOMEM;
 	}
 	while (wr) {
@@ -934,11 +936,13 @@ int c4iw_post_receive(struct ib_qp *ibqp, struct ib_recv_wr *wr,
 	spin_lock_irqsave(&qhp->lock, flag);
 	if (t4_wq_in_error(&qhp->wq)) {
 		spin_unlock_irqrestore(&qhp->lock, flag);
+		*bad_wr = wr;
 		return -EINVAL;
 	}
 	num_wrs = t4_rq_avail(&qhp->wq);
 	if (num_wrs == 0) {
 		spin_unlock_irqrestore(&qhp->lock, flag);
+		*bad_wr = wr;
 		return -ENOMEM;
 	}
 	while (wr) {