ns83820: spin_lock_irq() => spin_lock()

ns83820: spin_lock_irq() => spin_lock()

This is essentially cosmetic.  At this point the IRQs are already
disabled because we called spin_lock_irq(&dev->rx_info.lock).

The real bug here was fixed back in 2006 in 3a10ccebe: "[PATCH] lock
validator: fix ns83820.c irq-flags bug".  Prior to that patch, it was
a "spin_lock_irq is not nestable" type bug.  The 2006 patch changes the
unlock to not re-enable IRQs, which eliminates the potential deadlock.

But this bit was missed.  We should change the lock function as well so
it balances nicely.

Signed-off-by: Dan Carpenter <error27@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>