[IA64] vector-domain - handle assign_irq_vector(AUTO_ASSIGN)

This change fixes a panic when assign_irq_vector(irq) is called with
irq = AUTO_ASSIGN.

Signed-off-by: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
1 file changed