cudaMemset2D fix: Correct buffer height parameter

Changed the height parameter in the cudaMemset2D function call to use
minSSD_buf.rows instead of disp.rows. This enures the correct buffer
height is used for memory initialization.

modules/cudastereo/src/cuda/stereobm.cu

@@ -391,7 +391,7 @@ namespace cv { namespace cuda { namespace device
             //cudaSafeCall( cudaFuncSetCacheConfig(&stereoKernel, cudaFuncCachePreferShared) );
 
             cudaSafeCall( cudaMemset2D(disp.data, disp.step, 0, disp.cols, disp.rows) );
-            cudaSafeCall( cudaMemset2D(minSSD_buf.data, minSSD_buf.step, 0xFF, minSSD_buf.cols * minSSD_buf.elemSize(), disp.rows) );
+            cudaSafeCall( cudaMemset2D(minSSD_buf.data, minSSD_buf.step, 0xFF, minSSD_buf.cols * minSSD_buf.elemSize(), minSSD_buf.rows) );
 
             cudaSafeCall( cudaMemcpyToSymbol( cwidth, &left.cols, sizeof(left.cols) ) );
             cudaSafeCall( cudaMemcpyToSymbol( cheight, &left.rows, sizeof(left.rows) ) );