sunbmac: Remove unused local variable.

Commit eb716c54 ("sunbmac: remove
unnecessary setting of skb->dev") caused the local varible 'dev'
in bigmac_init_rings to become unused.  And now the compiler
warns about it.
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/sun/sunbmac.c

@@ -212,7 +212,6 @@ static void bigmac_clean_rings(struct bigmac *bp)
 static void bigmac_init_rings(struct bigmac *bp, int from_irq)
 {
 	struct bmac_init_block *bb = bp->bmac_block;
-	struct net_device *dev = bp->dev;
 	int i;
 	gfp_t gfp_flags = GFP_KERNEL;