staging: unisys: refactor visor_signalqueue_empty()

Rename visor_signalqueue_empty() to spar_signalqueue_empty(), and fix
CamelCase parameter names:

pChannel => ch
Queue => queue

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