fixed some warnings under linux

modules/gpu/src/filtering.cpp

@@ -810,7 +810,6 @@ Ptr<FilterEngine_GPU> cv::gpu::createSeparableLinearFilter_GPU(int srcType, int
     if (columnBorderType < 0)
         columnBorderType = rowBorderType;
 
-    int sdepth = CV_MAT_DEPTH(srcType), ddepth = CV_MAT_DEPTH(dstType);
     int cn = CV_MAT_CN(srcType);
     int bdepth = CV_32F;
     int bufType = CV_MAKETYPE(bdepth, cn);

modules/gpu/src/imgproc_gpu.cpp

@@ -341,7 +341,7 @@ void cv::gpu::copyMakeBorder(const GpuMat& src, GpuMat& dst, int top, int bottom
         }
     case CV_32FC1:
         {
-            float val = static_cast<float>(value[0]);
+            Npp32f val = static_cast<Npp32f>(value[0]);
             Npp32s nVal = *(reinterpret_cast<Npp32s*>(&val));
             nppSafeCall( nppiCopyConstBorder_32s_C1R(src.ptr<Npp32s>(), src.step, srcsz,
                 dst.ptr<Npp32s>(), dst.step, dstsz, top, left, nVal) );

modules/gpu/src/match_template.cpp

@@ -577,7 +577,7 @@ void cv::gpu::matchTemplate(const GpuMat& image, const GpuMat& templ, GpuMat& re
     static const Caller callers32F[] = { ::matchTemplate_SQDIFF_32F, 0, 
                                          ::matchTemplate_CCORR_32F, 0, 0, 0 };
 
-    const Caller* callers;
+    const Caller* callers = 0;
     switch (image.depth())
     {
         case CV_8U: callers = callers8U; break;

modules/gpu/src/stereobp.cpp

@@ -130,9 +130,7 @@ namespace
         {
             CV_Assert(0 < rthis.ndisp && 0 < rthis.iters && 0 < rthis.levels);
             CV_Assert(rthis.msg_type == CV_32F || rthis.msg_type == CV_16S);
-
-            if (rthis.msg_type == CV_16S)
-                CV_Assert((1 << (rthis.levels - 1)) * scale * rthis.max_data_term < numeric_limits<short>::max());
+            CV_Assert(rthis.msg_type == CV_32F || (1 << (rthis.levels - 1)) * scale * rthis.max_data_term < numeric_limits<short>::max());
         }
 
         void operator()(const GpuMat& left, const GpuMat& right, GpuMat& disp, cudaStream_t stream)