xsm: Use mapped IRQ not PIRQ in unmap_domain_pirq

XSM permissions are defined in terms of IRQs, not PIRQs; use the
correct number when checking permission in unmap_domain_pirq.

Signed-off-by: Daniel De Graaf <dgdegra@tycho.nsa.gov>
Committed-by: Keir Fraser <keir@xen.org>

xen/arch/x86/physdev.c

@@ -239,7 +239,7 @@ int physdev_unmap_pirq(domid_t domid, int pirq)
     if ( !IS_PRIV_FOR(current->domain, d) )
         goto free_domain;
 
-    ret = xsm_irq_permission(d, pirq, 0);
+    ret = xsm_irq_permission(d, domain_pirq_to_irq(d, pirq), 0);
     if ( ret )
         goto free_domain;