x86/amd-iommu: Fix suspend/resume with IOMMU

This is a suspend resume fix for 2.6.32-stable inclusion. The
problem with this patch is that it is not upstream because the code
changed with 2.6.33 and the function where this bug is in was
removed. So this fix does not make sense anymore for anything later than
2.6.32. The patch was tested by multiple partys and is confirmed to fix
the broken suspend/resume issue with the 2.6.32 kernel.

This patch fixes suspend/resume with AMD IOMMU enabled.
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

arch/x86/kernel/amd_iommu.c

@@ -544,7 +544,7 @@ static void flush_devices_by_domain(struct protection_domain *domain)
 
 	for (i = 0; i <= amd_iommu_last_bdf; ++i) {
 		if ((domain == NULL && amd_iommu_pd_table[i] == NULL) ||
-		    (amd_iommu_pd_table[i] != domain))
+		    (domain != NULL && amd_iommu_pd_table[i] != domain))
 			continue;
 
 		iommu = amd_iommu_rlookup_table[i];