[cuda] remove an unused variable

Author: Carsten Griwodz

src/cctag/cuda/tag.cu

@@ -277,8 +277,6 @@ void TagPipe::imageCenterOptLoop(
                                  ellipse.angle() );
     float2 f = make_float2( center.x(), center.y() );
 
-    cctag::geometry::matrix3x3 bestHomography;
-
     imageCenterOptLoop( tagIndex,
                         debug_numTags,
                         _tag_streams[tagIndex%NUM_ID_STREAMS],