Fix callback signature for --spice-debug option handling
Fix callback signature for --spice-debug option handling

The callback for option handling should return TRUE otherwise the
option parser will think parsing failed. The current 'void' return
type meant it was non-deterministic whether --spice-debug actually
worked or not

Signed-off-by: Daniel P. Berrange <bb938cf255e055ff3507f2627d214e8e62118fcf@redhat.com>

freedesktop-unofficial-mirror/spice__spice-gtk,SPICE/spice-gtk,dezelin/spice-gtk,SPICE/spice-gtk,guodong/spice-gtk,fgouget/spice-gtk,guodong/spice-gtk,mathslinux/spice-gtk,mathslinux/spice-gtk,dezelin/spice-gtk,flexVDI/spice-gtk,elmarco/spice-gtk,freedesktop-unofficial-mirror/spice__spice-gtk,dezelin/spice-gtk,SPICE/spice-gtk,guodong/spice-gtk,freedesktop-unofficial-mirror/spice__spice-gtk,elmarco/spice-gtk,Fantu/spice-gtk,fgouget/spice-gtk,flexVDI/spice-gtk,Fantu/spice-gtk,guodong/spice-gtk,elmarco/spice-gtk,SPICE/spice-gtk,fgouget/spice-gtk,Fantu/spice-gtk,dezelin/spice-gtk,mathslinux/spice-gtk,mathslinux/spice-gtk,freedesktop-unofficial-mirror/spice__spice-gtk,Fantu/spice-gtk,elmarco/spice-gtk