xen/arm: vGICv3: Restore the interrupt state correctly

xen/arm: vGICv3: Restore the interrupt state correctly

As "spin_lock_irqsave(&v->arch.vgic.lock, flags)" saves the current interrupt
state in "flags", "spin_unlock_irqrestore(&v->arch.vgic.lock, flags)" should be
used to restore the saved interrupt state.

Fixes: fe7fa1332dabd9ce4 ("ARM: vGICv3: handle virtual LPI pending and property tables")
Signed-off-by: Ayan Kumar Halder <ayankuma@amd.com>
Reviewed-by: Bertrand Marquis <bertrand.marquis@arm.com>
Reviewed-by: Andre Przywara <andre.przywara@arm.com>
Acked-by: Julien Grall <jgrall@amazon.com>
Release-acked-by: Henry Wang <Henry.Wang@arm.com>