iommu/amd: Fix missing iommu_shutdown initialization in passthrough mode

commit f2f12b6f upstream.

The iommu_shutdown callback is not initialized when the AMD
IOMMU driver runs in passthrough mode. Fix that by moving
the callback initialization before the check for
passthrough mode.
Signed-off-by: Shuah Khan <shuah.khan@hp.com>
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

drivers/iommu/amd_iommu_init.c

@@ -1468,6 +1468,8 @@ static int __init amd_iommu_init(void)
 
 	register_syscore_ops(&amd_iommu_syscore_ops);
 
+	x86_platform.iommu_shutdown = disable_iommus;
+
 	if (iommu_pass_through)
 		goto out;
 
@@ -1476,7 +1478,6 @@ static int __init amd_iommu_init(void)
 	else
 		printk(KERN_INFO "AMD-Vi: Lazy IO/TLB flushing enabled\n");
 
-	x86_platform.iommu_shutdown = disable_iommus;
 out:
 	return ret;