staging: vt6656: replace camel case from command variables

camel case changes
uCmdDequeueIdx -> cmd_dequeue_idx
uCmdEnqueueIdx -> cmd_enqueue_idx
cbFreeCmdQueue -> free_cmd_queue
bCmdRunning -> cmd_running

Signed-off-by: Malcolm Priestley <tvboxspy@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>