ide: small ide-scan-pci.c cleanup

- ide_scan_pcibus() can become static
- instead of ide_scan_pci() we can use ide_scan_pcibus() directly
  in module_init()

Signed-off-by: Adrian Bunk <bunk@kernel.org>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>

include/linux/ide.h

@@ -1017,7 +1017,6 @@ void ide_init_disk(struct gendisk *, ide_drive_t *);
 
 #ifdef CONFIG_IDEPCI_PCIBUS_ORDER
 extern int ide_scan_direction;
-int __init ide_scan_pcibus(void);
 extern int __ide_pci_register_driver(struct pci_driver *driver, struct module *owner, const char *mod_name);
 #define ide_pci_register_driver(d) __ide_pci_register_driver(d, THIS_MODULE, KBUILD_MODNAME)
 #else