iommu/arm-smmu-v3: Fix resource_size check

This is an off-by-one mistake.

resource_size() returns res->end - res->start + 1.
Reviewed-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Will Deacon <will@kernel.org>

drivers/iommu/arm-smmu-v3.c

@@ -3632,7 +3632,7 @@ static int arm_smmu_device_probe(struct platform_device *pdev)
 
 	/* Base address */
 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
-	if (resource_size(res) + 1 < arm_smmu_resource_size(smmu)) {
+	if (resource_size(res) < arm_smmu_resource_size(smmu)) {
 		dev_err(dev, "MMIO region too small (%pr)\n", res);
 		return -EINVAL;
 	}