fixed docs

doc/gpu_data_structures.tex

@@ -54,7 +54,7 @@ template<typename T> struct PtrStep_
 
 \end{lstlisting}
 
-\cvclass{gpu::PtrElemStrp\_}\
+\cvclass{gpu::PtrElemStrp\_}
 This is structure is similar to DevMem2D\_ but contains only pointer and row step in elements. Width and height fields are excluded due to performance reasons. This class is can only be constructed if sizeof(T) is a multiple of 256. The structure is for internal use or for users who write own device code.
 
 \begin{lstlisting}
@@ -272,4 +272,4 @@ Ensures that size of matrix is big enough and matrix has proper type. The functi
 \end{description}
 
 Also the following wrapper is available:
-\cvdefCpp{void ensureSizeIsEnough(Size size, int type, GpuMat\& m);}
+\cvdefCpp{void ensureSizeIsEnough(Size size, int type, GpuMat\& m);}