soc/intel/common/block/smbus: Use `pci_dev_read_resources()` in read resources

scan-build found a dead assignment, that the value stored to `res` is
never read. Use `pci_dev_read_resources()` instead, as done in
`sb/intel/common/smbus_ops.c` since commit 5f734327
(sb/intel/common/smbus_ops.c: Clean up read resources) avoiding the
assignment.

Change-Id: Ic59063b05a45dca411bf5b56c1abf3dd66ff0437
Found-by: scan-build (coreboot toolchain v0ad5fbd48d 2020-12-24 - clang version 11.0.0)
Signed-off-by: Paul Menzel <pmenzel@molgen.mpg.de>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/54904
Reviewed-by: Arthur Heymans <arthur@aheymans.xyz>
Reviewed-by: Angel Pons <th3fanbus@gmail.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
diff --git a/src/soc/intel/common/block/smbus/smbus.c b/src/soc/intel/common/block/smbus/smbus.c
index bc906a6..bb95b76 100644
--- a/src/soc/intel/common/block/smbus/smbus.c
+++ b/src/soc/intel/common/block/smbus/smbus.c
@@ -53,15 +53,14 @@
 
 static void smbus_read_resources(struct device *dev)
 {
+	pci_dev_read_resources(dev);
+
 	struct resource *res = new_resource(dev, PCI_BASE_ADDRESS_4);
 	res->base = SMBUS_IO_BASE;
 	res->size = 32;
 	res->limit = res->base + res->size - 1;
 	res->flags = IORESOURCE_IO | IORESOURCE_FIXED | IORESOURCE_RESERVE |
 		     IORESOURCE_STORED | IORESOURCE_ASSIGNED;
-
-	/* Also add MMIO resource */
-	res = pci_get_resource(dev, PCI_BASE_ADDRESS_0);
 }
 
 static struct device_operations smbus_ops = {