pci-label.c: size_t misspelled as mode_t

no, really, strlen() and snprintf() do not return mode_t values...
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

drivers/pci/pci-label.c

@@ -55,7 +55,7 @@ enum smbios_attr_enum {
 	SMBIOS_ATTR_INSTANCE_SHOW,
 };
 
-static mode_t
+static size_t
 find_smbios_instance_string(struct pci_dev *pdev, char *buf,
 			    enum smbios_attr_enum attribute)
 {