iommu/amd: Remove redundant assignment to variable npages

The variable npages is being initialized however this is never read and
later it is being reassigned to a new value. The initialization is
redundant and hence can be removed.

Addresses-Coverity: ("Unused Value")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>

drivers/iommu/amd_iommu.c

@@ -2609,7 +2609,7 @@ static void unmap_sg(struct device *dev, struct scatterlist *sglist,
 	struct protection_domain *domain;
 	struct dma_ops_domain *dma_dom;
 	unsigned long startaddr;
-	int npages = 2;
+	int npages;
 
 	domain = get_domain(dev);
 	if (IS_ERR(domain))