[DRIVERS] smc91x: Temporary fix for probe function

This patch fix probe function smc91x driver which is broken
after we made unlocked value of spin lock as 0xFFFFFFFF.

Although, this is just temprorary fix. The smc91x driver has
lot of commented code which need to be enabled for cleaner fix.

Signed-off-by: Anup Patel <anup@brainfault.org>