iommu/amd-vi: fix assert comparing boolean to enum

Or else when iommu_intremap is set to iommu_intremap_full the assert
triggers.

Fixes: 1ba66a870e ('AMD/IOMMU: without XT, x2APIC needs to be forced into physical mode')
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>

xen/drivers/passthrough/amd/pci_amd_iommu.c

@@ -240,7 +240,7 @@ static int __must_check amd_iommu_setup_domain_device(
          */
         if ( dte->it_root )
             ASSERT(dte->int_ctl == IOMMU_DEV_TABLE_INT_CONTROL_TRANSLATED);
-        ASSERT(dte->iv == iommu_intremap);
+        ASSERT(dte->iv == !!iommu_intremap);
         ASSERT(dte->ex == ivrs_dev->dte_allow_exclusion);
         ASSERT(dte->sys_mgt == MASK_EXTR(ivrs_dev->device_flags,
                                          ACPI_IVHD_SYSTEM_MGMT));