net: dm9000: Fix build

Commit c88fcb (net: dm9000: convert to hw_features) broke the build of
the dm9000 driver since it merged functions which use different names
for the board info structure used for I/O operations without updating
all the references to use the same name. Fix that.
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/dm9000.c

@@ -768,7 +768,7 @@ dm9000_init_dm9000(struct net_device *dev)
 
 	/* Checksum mode */
 	if (dev->hw_features & NETIF_F_RXCSUM)
-		iow(dm, DM9000_RCSR,
+		iow(db, DM9000_RCSR,
 			(dev->features & NETIF_F_RXCSUM) ? RCSR_CSUM : 0);
 
 	iow(db, DM9000_GPCR, GPCR_GEP_CNTL);	/* Let GPIO0 output */