staging: unisys: fix CamelCase controlvm globals

Fix the CamelCase variable names:
Periodic_controlvm_work => periodic_controlvm_work
Periodic_controlvm_workqueue => periodic_controlvm_workqueue

Update all references to use the corrected names.

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