rtlwifi: rtl8192de: 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>

drivers/net/wireless/rtlwifi/rtl8192de/trx.c

@@ -587,6 +587,11 @@ void rtl92de_tx_fill_desc(struct ieee80211_hw *hw,
 	buf_len = skb->len;
 	mapping = pci_map_single(rtlpci->pdev, skb->data, skb->len,
 				 PCI_DMA_TODEVICE);
+	if (pci_dma_mapping_error(rtlpci->pdev, mapping)) {
+		RT_TRACE(rtlpriv, COMP_SEND, DBG_TRACE,
+			 "DMA mapping error");
+		return;
+	}
 	CLEAR_PCI_TX_DESC_CONTENT(pdesc, sizeof(struct tx_desc_92d));
 	if (ieee80211_is_nullfunc(fc) || ieee80211_is_ctl(fc)) {
 		firstseg = true;
@@ -740,6 +745,11 @@ void rtl92de_tx_fill_cmddesc(struct ieee80211_hw *hw,
 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)(skb->data);
 	__le16 fc = hdr->frame_control;
 
+	if (pci_dma_mapping_error(rtlpci->pdev, mapping)) {
+		RT_TRACE(rtlpriv, COMP_SEND, DBG_TRACE,
+			 "DMA mapping error");
+		return;
+	}
 	CLEAR_PCI_TX_DESC_CONTENT(pdesc, TX_DESC_SIZE);
 	if (firstseg)
 		SET_TX_DESC_OFFSET(pdesc, USB_HWDESC_HEADER_LEN);