staging: unisys: fix CamelCased ControlVM globals

Fix the CamelCase global names:

ControlVm_Pending_Msg => controlvm_pending_msg
ControlVm_Pending_Msg_Valid => controlvm_pending_msg_valid

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>