[PATCH] PCI: add missing checks in drivers/pci/probe.c.

[PATCH] PCI: add missing checks in drivers/pci/probe.c.

 I noticed drivers/pci/probe.c::pci_scan_bus_parented() has some functions which
the return value is not checked.

 The patch bellow adds the check for device_register(), class_device_register(),
class_device_create_file() and sysfs_create_link().

(hope the error label names are not too ugly).

Signed-off-by: Luiz Capitulino <lcapitulino@conectiva.com.br>
Signed-off-by: Greg Kroah-Hartman <greg@kroah.com>