x86/irq: Check vector allocation early

__assign_irq_vector() uses the vector_cpumask which is assigned by
apic->vector_allocation_domain() without doing basic sanity checks. That can
result in a situation where the final assignement of a newly found vector
fails in apic->cpu_mask_to_apicid_and(). So we have to do rollbacks for no
reason.

apic->cpu_mask_to_apicid_and() only fails if 

  vector_cpumask & requested_cpumask & cpu_online_mask 

is empty.

Check for this condition right away and if the result is empty try immediately
the next possible cpu in the requested mask. So in case of a failure the old
setting is unchanged and we can remove the rollback code.

Signed-off-by: Thomas Gleixner <[email protected]>
Tested-by: Borislav Petkov <[email protected]>
Tested-by: Joe Lawrence <[email protected]>
Cc: Jiang Liu <[email protected]>
Cc: Jeremiah Mahler <[email protected]>
Cc: [email protected]
Cc: Guenter Roeck <[email protected]>
Cc: [email protected] #4.3+
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Thomas Gleixner <[email protected]>

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