smsc911x: fix platform resource call during module unload

This patch fixes a typo, the platform_get_resource calls in
smsc911x_drv_remove are supposed to look the same as those in
smsc911x_drv_probe.

Reported and fixed by dfoley@telus.net.

Signed-off-by: Steve Glendinning <steve.glendinning@smsc.com>
Signed-off-by: David S. Miller <davem@davemloft.net>