Pull x86 fixes from Ingo Molnar:
"Two boot crash fixes and an IRQ handling crash fix"
* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/apic: Handle zero vector gracefully in clear_vector_irq()
Revert "x86/mm/32: Set NX in __supported_pte_mask before enabling paging"
xen/qspinlock: Don't kick CPU if IRQ is not initialized