src/southbridge/intel/i82801gx/pcie.c: Correct NULL check

Check if `pcie_dev` is NULL instead of `dev`. This was flagged
as REVERSE_INULL during a Coverity scan, but is a simple typo.

Signed-off-by: Jacob Garber <jgarber1@ualberta.ca>
Change-Id: Idc40574b9341d1b10cb2136cbc1a865efa3ab3ee
Reviewed-on: https://review.coreboot.org/c/coreboot/+/31866
Reviewed-by: HAOUAS Elyes <ehaouas@noos.fr>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

src/southbridge/intel/i82801gx/pcie.c

@@ -195,7 +195,7 @@ static void root_port_commit_config(struct device *dev)
 
 		pcie_dev = rpc.ports[i];
 
-		if (dev == NULL) {
+		if (pcie_dev == NULL) {
 			printk(BIOS_ERR, "Root Port %d device is NULL?\n",
 			       i + 1);
 			continue;