x86/apic/vector: Ignore set_affinity call for inactive interrupts

The core interrupt code can call the affinity setter for inactive
interrupts under certain circumstances.

For inactive intererupts which use managed or reservation mode this is a
pointless exercise as the activation will assign a vector which fits the
destination mask.

Check for this and return w/o going through the vector assignment.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>