frv/PCI: Remove unused pci_root_bus

pci_root_bus is unused, so remove all references to it.
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

arch/frv/mb93090-mb00/pci-frv.h

@@ -31,7 +31,6 @@ void pcibios_resource_survey(void);
 /* pci-vdk.c */
 
 extern int __nongpreldata pcibios_last_bus;
-extern struct pci_bus *__nongpreldata pci_root_bus;
 extern struct pci_ops *__nongpreldata pci_root_ops;
 
 /* pci-irq.c */

arch/frv/mb93090-mb00/pci-vdk.c

@@ -26,7 +26,6 @@
 unsigned int __nongpreldata pci_probe = 1;
 
 int  __nongpreldata pcibios_last_bus = -1;
-struct pci_bus *__nongpreldata pci_root_bus;
 struct pci_ops *__nongpreldata pci_root_ops;
 
 /*
@@ -416,8 +415,7 @@ int __init pcibios_init(void)
 	printk("PCI: Probing PCI hardware\n");
 	pci_add_resource(&resources, &pci_ioport_resource);
 	pci_add_resource(&resources, &pci_iomem_resource);
-	pci_root_bus = pci_scan_root_bus(NULL, 0, pci_root_ops, NULL,
-					 &resources);
+	pci_scan_root_bus(NULL, 0, pci_root_ops, NULL, &resources);
 
 	pcibios_irq_init();
 	pcibios_fixup_peer_bridges();