iommu/amd: Fix recently introduced compile warnings

Fix two compile warnings about unused variables introduced
by commit ecef115.

Reported-by: Paul Bolle <pebolle@tiscali.nl>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
diff --git a/drivers/iommu/amd_iommu.c b/drivers/iommu/amd_iommu.c
index bd8003d9..4aec6a2 100644
--- a/drivers/iommu/amd_iommu.c
+++ b/drivers/iommu/amd_iommu.c
@@ -3499,8 +3499,6 @@
 {
 	struct iommu_dev_data *dev_data;
 	struct pci_dev *dev = NULL;
-	struct amd_iommu *iommu;
-	u16 devid;
 	int ret;
 
 	ret = alloc_passthrough_domain();