bay: exit if notify handler cannot be installed

If acpi_install_notify_handler() for a bay device fails, the bay driver is
superfluous.  Most likely, another driver (like libata) is already caring
about this device anyway.  Furthermore,
register_hotplug_dock_device(acpi_handle) from the dock driver must not be
called twice with the same handler.  This would result in an endless loop
consuming 100% of CPU.  So clean up and exit.

Signed-off-by: Holger Macht <hmacht@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Len Brown <len.brown@intel.com>