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

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

[ Upstream commit ed51efd2ce44091a858ad829f666727e7c95695e ]

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: 1ac5a4047975 ("RDMA/bnxt_re: Add bnxt_re RoCE driver")
Fixes: 6e04b1035689 ("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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>