smsc95xx: fix reset check

The reset loop check should check the MII_BMCR register value for
BMCR_RESET rather than for MII_BMCR (the register address, which also
happens to be zero).

Signed-off-by: Rabin Vincent <rabin@rab.in>
Signed-off-by: David S. Miller <davem@davemloft.net>