minor chnages in GPU samples

samples/gpu/multi.cpp

@@ -50,7 +50,6 @@ CUcontext contexts[2];
 int main()
 {
     int num_devices = getCudaEnabledDeviceCount();
-
     if (num_devices < 2)
     {
         cout << "Two or more GPUs are required\n";
@@ -69,6 +68,7 @@ int main()
         }
     }
 
+    // Init CUDA Driver API
     safeCall(cuInit(0));
 
     // Create context for GPU #0

samples/gpu/performance/performance.h

@@ -71,7 +71,7 @@ public:
 
 private:
     TestSystem(): can_flush_(false), cpu_elapsed_(0), gpu_elapsed_(0), 
-                  speedup_total_(0.0), num_subtests_called_(0) {};
+                  speedup_total_(0.0), num_subtests_called_(0) {}
 
     void flushSubtestData();
 
@@ -135,4 +135,4 @@ void gen(cv::Mat& mat, int rows, int cols, int type, cv::Scalar low,
 
 std::string abspath(const std::string& relpath);
 
-#endif // OPENCV_GPU_SAMPLE_PERFORMANCE_H_
+#endif // OPENCV_GPU_SAMPLE_PERFORMANCE_H_
\ No newline at end of file

samples/gpu/stereo_multi.cpp

@@ -78,7 +78,6 @@ int main(int argc, char** argv)
     }
 
     int num_devices = getCudaEnabledDeviceCount();
-
     if (num_devices < 2)
     {
         cout << "Two or more GPUs are required\n";
@@ -111,6 +110,7 @@ int main(int argc, char** argv)
         return -1;
     }
 
+    // Init CUDA Driver API
     safeCall(cuInit(0));
 
     // Create context for the first GPU