sh: pci: Do PCI error check on own line

Instead of an "if" condition with a line split, use the usual error
handling pattern with a separate variable to improve readability.

No functional changes intended.

Link: https://lore.kernel.org/r/20230911125354.25501-3-ilpo.jarvinen@linux.intel.com
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
[bhelgaas: u16 vid, PCI_POSSIBLE_ERROR()]
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>

Author: ij-intel

arch/sh/drivers/pci/common.c

@@ -50,20 +50,21 @@ int __init pci_is_66mhz_capable(struct pci_channel *hose,
 				int top_bus, int current_bus)
 {
 	u32 pci_devfn;
-	unsigned short vid;
+	u16 vid;
 	int cap66 = -1;
 	u16 stat;
+	int ret;
 
 	pr_info("PCI: Checking 66MHz capabilities...\n");
 
 	for (pci_devfn = 0; pci_devfn < 0xff; pci_devfn++) {
 		if (PCI_FUNC(pci_devfn))
 			continue;
-		if (early_read_config_word(hose, top_bus, current_bus,
-					   pci_devfn, PCI_VENDOR_ID, &vid) !=
-		    PCIBIOS_SUCCESSFUL)
+		ret = early_read_config_word(hose, top_bus, current_bus,
+					     pci_devfn, PCI_VENDOR_ID, &vid);
+		if (ret != PCIBIOS_SUCCESSFUL)
 			continue;
-		if (vid == 0xffff)
+		if (PCI_POSSIBLE_ERROR(vid))
 			continue;
 
 		/* check 66MHz capability */