x86: io-apic - get rid of __DO_ACTION macro

Replace __DO_ACTION macro with io_apic_modify_irq function.
This allow us to 'grep' definitions being hided by
__DO_ACTION macro:

	__unmask_IO_APIC_irq
	__mask_IO_APIC_irq
	__mask_and_edge_IO_APIC_irq
	__unmask_and_level_IO_APIC_irq

Signed-off-by: Cyrill Gorcunov <gorcunov@gmail.com>
Acked-by: Yinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>