rtlwifi: rtl8192se: 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: NLarry Finger <Larry.Finger@lwfinger.net>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

drivers/net/wireless/rtlwifi/rtl8192se/trx.c

@@ -611,6 +611,11 @@ void rtl92se_tx_fill_desc(struct ieee80211_hw *hw,
 		    PCI_DMA_TODEVICE);
 	u8 bw_40 = 0;
 
+	if (pci_dma_mapping_error(rtlpci->pdev, mapping)) {
+		RT_TRACE(rtlpriv, COMP_SEND, DBG_TRACE,
+			 "DMA mapping error");
+		return;
+	}
 	if (mac->opmode == NL80211_IFTYPE_STATION) {
 		bw_40 = mac->bw_40;
 	} else if (mac->opmode == NL80211_IFTYPE_AP ||
@@ -763,6 +768,7 @@ void rtl92se_tx_fill_desc(struct ieee80211_hw *hw,
 void rtl92se_tx_fill_cmddesc(struct ieee80211_hw *hw, u8 *pdesc,
 	bool firstseg, bool lastseg, struct sk_buff *skb)
 {
+	struct rtl_priv *rtlpriv = rtl_priv(hw);
 	struct rtl_pci *rtlpci = rtl_pcidev(rtl_pcipriv(hw));
 	struct rtl_hal *rtlhal = rtl_hal(rtl_priv(hw));
 	struct rtl_tcb_desc *tcb_desc = (struct rtl_tcb_desc *)(skb->cb);
@@ -770,7 +776,12 @@ void rtl92se_tx_fill_cmddesc(struct ieee80211_hw *hw, u8 *pdesc,
 	dma_addr_t mapping = pci_map_single(rtlpci->pdev, skb->data, skb->len,
 			PCI_DMA_TODEVICE);
 
-    /* Clear all status	*/
+	if (pci_dma_mapping_error(rtlpci->pdev, mapping)) {
+		RT_TRACE(rtlpriv, COMP_SEND, DBG_TRACE,
+			 "DMA mapping error");
+		return;
+	}
+	/* Clear all status	*/
 	CLEAR_PCI_TX_DESC_CONTENT(pdesc, TX_CMDDESC_SIZE_RTL8192S);
 
 	/* This bit indicate this packet is used for FW download. */