PCIE: check and return bus_register errors

Have pcie_port_bus_register() notice and return errors.
Mark it __must_check so that its caller(s) must check its return value.

Signed-off-by: Randy Dunlap <[e-mail]>
Signed-off-by: Greg Kroah-Hartman <[e-mail]>

drivers/pci/pcie/portdrv.h

···
 extern int pcie_port_device_resume(struct pci_dev *dev);
 #endif
 extern void pcie_port_device_remove(struct pci_dev *dev);
-extern void pcie_port_bus_register(void);
+extern int pcie_port_bus_register(void);
 extern void pcie_port_bus_unregister(void);
 
 #endif /* _PORTDRV_H_ */

drivers/pci/pcie/portdrv_core.c

···
  * Copyright (C) Tom Long Nguyen ([e-mail])
  */
 
+#include <linux/compiler.h>
 #include <linux/module.h>
 #include <linux/pci.h>
 #include <linux/kernel.h>
···
 		pci_disable_msi(dev);
 }
 
-void pcie_port_bus_register(void)
+int __must_check pcie_port_bus_register(void)
 {
-	bus_register(&pcie_port_bus_type);
+	return bus_register(&pcie_port_bus_type);
 }
 
 void pcie_port_bus_unregister(void)

drivers/pci/pcie/portdrv_pci.c

···
 
 static int __init pcie_portdrv_init(void)
 {
-	int retval = 0;
+	int retval;
 
-	pcie_port_bus_register();
+	retval = pcie_port_bus_register();
+	if (retval) {
+		printk(KERN_WARNING "PCIE: bus_register error: %d\n", retval);
+		goto out;
+	}
 	retval = pci_register_driver(&pcie_portdrv);
 	if (retval)
 		pcie_port_bus_unregister();
+ out:
 	return retval;
 }