RDMA/bnxt_re: Avoid accessing nq->bar_reg_iomem in failure case

In the failure path, nq->bar_reg_iomem gets accessed without
initializing. Avoid this by calling the bnxt_qplib_nq_stop_irq only if the
initialization is complete.
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Fixes: 1ac5a404 ("RDMA/bnxt_re: Add bnxt_re RoCE driver")
Fixes: 6e04b103 ("RDMA/bnxt_re: Fix broken RoCE driver due to recent L2 driver changes")
Signed-off-by: Selvin Xavier <selvin.xavier@broadcom.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

drivers/infiniband/hw/bnxt_re/qplib_fp.c

@@ -358,7 +358,8 @@ void bnxt_qplib_disable_nq(struct bnxt_qplib_nq *nq)
 	}
 
 	/* Make sure the HW is stopped! */
-	bnxt_qplib_nq_stop_irq(nq, true);
+	if (nq->requested)
+		bnxt_qplib_nq_stop_irq(nq, true);
 
 	if (nq->bar_reg_iomem)
 		iounmap(nq->bar_reg_iomem);