rtlwifi: Fix warning for unchecked pci_map_single() call

Kernel 3.8 implements checking of all DMA mapping calls and issues
a WARNING for the first it finds that is not checked.

Signed-off-by: Larry Finger <Larry.Finger@lwfinger.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/drivers/net/wireless/rtlwifi/pci.c b/drivers/net/wireless/rtlwifi/pci.c
index 3deacaf..4261e8e 100644
--- a/drivers/net/wireless/rtlwifi/pci.c
+++ b/drivers/net/wireless/rtlwifi/pci.c
@@ -743,6 +743,8 @@
 
 done:
 		bufferaddress = (*((dma_addr_t *)skb->cb));
+		if (pci_dma_mapping_error(rtlpci->pdev, bufferaddress))
+			return;
 		tmp_one = 1;
 		rtlpriv->cfg->ops->set_desc((u8 *) pdesc, false,
 					    HW_DESC_RXBUFF_ADDR,
@@ -1115,6 +1117,10 @@
 					   PCI_DMA_FROMDEVICE);
 
 			bufferaddress = (*((dma_addr_t *)skb->cb));
+			if (pci_dma_mapping_error(rtlpci->pdev, bufferaddress)) {
+				dev_kfree_skb_any(skb);
+				return 1;
+			}
 			rtlpriv->cfg->ops->set_desc((u8 *)entry, false,
 						    HW_DESC_RXBUFF_ADDR,
 						    (u8 *)&bufferaddress);