Spidernet Remove unused variable

Remove unused variable; this makes code easier to read.
Tweak commentary.

Signed-off-by: Linas Vepstas <linas@austin.ibm.com>
Cc: James K Lewis <jklewis@us.ibm.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Jeff Garzik <jeff@garzik.org>

drivers/net/spider_net.c

@@ -367,21 +367,20 @@ spider_net_free_rx_chain_contents(struct spider_net_card *card)
 }
 
 /**
- * spider_net_prepare_rx_descr - reinitializes a rx descriptor
+ * spider_net_prepare_rx_descr - Reinitialize RX descriptor
  * @card: card structure
  * @descr: descriptor to re-init
  *
- * return 0 on succes, <0 on failure
+ * Return 0 on succes, <0 on failure.
  *
- * allocates a new rx skb, iommu-maps it and attaches it to the descriptor.
- * Activate the descriptor state-wise
+ * Allocates a new rx skb, iommu-maps it and attaches it to the
+ * descriptor. Mark the descriptor as activated, ready-to-use.
  */
 static int
 spider_net_prepare_rx_descr(struct spider_net_card *card,
 			    struct spider_net_descr *descr)
 {
 	dma_addr_t buf;
-	int error = 0;
 	int offset;
 	int bufsize;
 
@@ -409,7 +408,7 @@ spider_net_prepare_rx_descr(struct spider_net_card *card,
 		(SPIDER_NET_RXBUF_ALIGN - 1);
 	if (offset)
 		skb_reserve(descr->skb, SPIDER_NET_RXBUF_ALIGN - offset);
-	/* io-mmu-map the skb */
+	/* iommu-map the skb */
 	buf = pci_map_single(card->pdev, descr->skb->data,
 			SPIDER_NET_MAX_FRAME, PCI_DMA_FROMDEVICE);
 	descr->buf_addr = buf;
@@ -424,7 +423,7 @@ spider_net_prepare_rx_descr(struct spider_net_card *card,
 					 SPIDER_NET_DMAC_NOINTR_COMPLETE;
 	}
 
-	return error;
+	return 0;
 }
 
 /**