From: Manfred Spraul <manfred@colorfullife.com>

apm.c:suspend() calls set_system_power_state() under (effectively)
spin_lock_irq(i8253_lock).

But set_system_power_state() unconditionally enables interrupts, in
apm_bios_call_simple().  This generates nasty warnings from the uniprocessor
spinlock debugging code, and would be deadlocky if APM worked on SMP.

So drop the locks around the set_system_power_state() call.