x86: I/O APIC: clean up after a fasteoi failure

Disable the 8259A when routing of the timer interrupt through the chip to
the local APIC of the primary processor has failed.

Signed-off-by: Maciej W. Rozycki <macro@linux-mips.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>