RDMA/bnxt_re: Avoid NULL check after accessing the pointer

This is reported by smatch check.  rcfw->creq_bar_reg_iomem is accessed in
bnxt_qplib_rcfw_stop_irq and this variable check afterwards doesn't make
sense.  Also, rcfw->creq_bar_reg_iomem will never be NULL.  So Removing
this check.
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
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_rcfw.c

@@ -615,13 +615,8 @@ void bnxt_qplib_disable_rcfw_channel(struct bnxt_qplib_rcfw *rcfw)
 
 	bnxt_qplib_rcfw_stop_irq(rcfw, true);
 
-	if (rcfw->cmdq_bar_reg_iomem)
-		iounmap(rcfw->cmdq_bar_reg_iomem);
-	rcfw->cmdq_bar_reg_iomem = NULL;
-
-	if (rcfw->creq_bar_reg_iomem)
-		iounmap(rcfw->creq_bar_reg_iomem);
-	rcfw->creq_bar_reg_iomem = NULL;
+	iounmap(rcfw->cmdq_bar_reg_iomem);
+	iounmap(rcfw->creq_bar_reg_iomem);
 
 	indx = find_first_bit(rcfw->cmdq_bitmap, rcfw->bmap_size);
 	if (indx != rcfw->bmap_size)
@@ -630,6 +625,8 @@ void bnxt_qplib_disable_rcfw_channel(struct bnxt_qplib_rcfw *rcfw)
 	kfree(rcfw->cmdq_bitmap);
 	rcfw->bmap_size = 0;
 
+	rcfw->cmdq_bar_reg_iomem = NULL;
+	rcfw->creq_bar_reg_iomem = NULL;
 	rcfw->aeq_handler = NULL;
 	rcfw->vector = 0;
 }
@@ -713,6 +710,8 @@ int bnxt_qplib_enable_rcfw_channel(struct pci_dev *pdev,
 	if (!rcfw->creq_bar_reg_iomem) {
 		dev_err(&rcfw->pdev->dev, "CREQ BAR region %d mapping failed\n",
 			rcfw->creq_bar_reg);
+		iounmap(rcfw->cmdq_bar_reg_iomem);
+		rcfw->cmdq_bar_reg_iomem = NULL;
 		return -ENOMEM;
 	}
 	rcfw->creq_qp_event_processed = 0;