net: pxa168_eth: avoid using signed char for bitops

Signedness bugs may occur when using signed char for bitops,
depending on if the highest bit is ever used.

Signed-off-by: Antoine Tenart <[e-mail]>
Reported-by: Dan Carpenter <[e-mail]>
Signed-off-by: David S. Miller <[e-mail]>

drivers/net/ethernet/marvell/pxa168_eth.c

···
 	memcpy(oldMac, dev->dev_addr, ETH_ALEN);
 	memcpy(dev->dev_addr, sa->sa_data, ETH_ALEN);
 
-	mac_h = sa->sa_data[0] << 24;
-	mac_h |= sa->sa_data[1] << 16;
-	mac_h |= sa->sa_data[2] << 8;
-	mac_h |= sa->sa_data[3];
-	mac_l = sa->sa_data[4] << 8;
-	mac_l |= sa->sa_data[5];
+	mac_h = dev->dev_addr[0] << 24;
+	mac_h |= dev->dev_addr[1] << 16;
+	mac_h |= dev->dev_addr[2] << 8;
+	mac_h |= dev->dev_addr[3];
+	mac_l = dev->dev_addr[4] << 8;
+	mac_l |= dev->dev_addr[5];
 	wrl(pep, MAC_ADDR_HIGH, mac_h);
 	wrl(pep, MAC_ADDR_LOW, mac_l);