staging: unisys: fix CamelCased notifier globals

Fix these CamelCased names:

BusDev_Server_Notifiers => busdev_server_notifiers
BusDev_Client_Notifiers => busdev_client_notifiers

Update references to use the fixed names.

Signed-off-by: Benjamin Romer <benjamin.romer@unisys.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>