staging: unisys: fix CamelCase channel name ControlVm_channel

Rename the channel:

ControlVm_channel => controlvm_channel

Update all references to use the new name. Fix the odd bracketing in the
while() statement with the reference to controlvm_channel, too, so the
patch doesn't generate a warning.
Signed-off-by: Benjamin Romer <benjamin.romer@unisys.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>