staging/android: remove pointless sync_timeline_signal at destroy phase

All changes to timeline value come through the user via
sync_timeline_signal() calls. When sync_timeline_destroy() is called no
changes on timeline->value happens hence call sync_timeline_signal() with
no increment is pointless.

Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
Reviewed-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>