IB/hfi1: Add the break statement that was removed in an earlier patch

The break statement was unintentionally removed in this patch
commit 41ca419abc0ca7ee65d765408cdc1a7fed2897a3
("staging/rdma/hfi1: Remove hfi1 MR and hfi1 specific qp type")
Reviewed-by: Mike Marciniszyn <mike.marciniszyn@intel.com>
Signed-off-by: Harish Chegondi <harish.chegondi@intel.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

drivers/staging/rdma/hfi1/ruc.c

@@ -470,6 +470,7 @@ static void ruc_loopback(struct rvt_qp *sqp)
 			goto inv_err;
 do_write:
 		if (wqe->length == 0)
+			break;
 		if (unlikely(!rvt_rkey_ok(qp, &qp->r_sge.sge, wqe->length,
 					  wqe->rdma_wr.remote_addr,
 					  wqe->rdma_wr.rkey,