staging: unisys: Fix CamelCase in Issue_VMCALL_IO_CONTROLVM_ADDR()

Fix CamelCase names:
Issue_VMCALL_IO_CONTROLVM_ADDR => issue_vmcall_io_controlvm_addr
ControlAddress => control_addr
ControlBytes => control_bytes

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