staging: slicoss: Add error check for pci_map_single

Currently, DMA mapping failure is not detected, causing the hardware
to attempt a DMA from an invalid address.

This patch adds the corresponding error check for pci_map_single i.e.
pci_dma_mapping_error.

Problem found using the following Coccinelle semantic patch:
// <smpl>
@@
expression e1;
identifier x;
@@
 x=
(
*dma_map_single(...)
|
*dma_map_page(...)
)
... when != dma_mapping_error(e1,x)
@@
expression e1;
identifier x;
@@

 x =
(
*pci_map_single(...)
|
*pci_map_page(...)
)
 ... when != pci_dma_mapping_error(e1,x)
// </smpl>
Signed-off-by: Amitoj Kaur Chawla <amitoj1606@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/slicoss/slicoss.c

@@ -1855,6 +1855,11 @@ static void slic_xmit_build_request(struct adapter *adapter,
 	ihcmd->u.slic_buffers.totlen = skb->len;
 	phys_addr = pci_map_single(adapter->pcidev, skb->data, skb->len,
 			PCI_DMA_TODEVICE);
+	if (pci_dma_mapping_error(adapter->pcidev, phys_addr)) {
+		kfree_skb(skb);
+		dev_err(&adapter->pcidev->dev, "DMA mapping error\n");
+		return;
+	}
 	ihcmd->u.slic_buffers.bufs[0].paddrl = SLIC_GET_ADDR_LOW(phys_addr);
 	ihcmd->u.slic_buffers.bufs[0].paddrh = SLIC_GET_ADDR_HIGH(phys_addr);
 	ihcmd->u.slic_buffers.bufs[0].length = skb->len;