device-drivers/pci: Fix pci_scan_slot()

The test code scans the devices on a bus one by one. Then it calls
pci_scan_slot(). But pci_scan_slot cannot be called with non-zero
devfn (i.e. devfn % 8 shall be zero).

Signed-off-by: Tianyu <[email protected]>
Acked-by: Jiri Slaby <[email protected]>
Acked-by: Cyril Hrubis <[email protected]>

Author: tianyu

testcases/kernel/device-drivers/pci/tpci_kernel/ltp_tpci.c

@@ -321,6 +321,9 @@ static int test_slot_scan(void)
 
 	prk_info("scan pci slot");
 
+	if ((num % 8) != 0)
+		return TPASS;
+
 	ret = pci_scan_slot(bus, num);
 	if (ret >= 0) {
 		prk_info("found '%d' devices from scan slot", ret);