[SUNGEM]: fix minor bug in sungem.h

This changes the Sun Gem Ether driver's tx ring buffer 
length to the proper constant.  Currently TX_RING_SIZE 
and RX_RING_SIZE are equal, so no malfunction occurs.

Signed-off-by: Geoff Levand <geoffrey.levand@am.sony.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/sungem.h

@@ -1020,7 +1020,7 @@ struct gem {
 
 	struct gem_init_block	*init_block;
 	struct sk_buff		*rx_skbs[RX_RING_SIZE];
-	struct sk_buff		*tx_skbs[RX_RING_SIZE];
+	struct sk_buff		*tx_skbs[TX_RING_SIZE];
 	dma_addr_t		gblock_dvma;
 
 	struct pci_dev		*pdev;