fixed various warnings and obvious errors reported by clang compiler and the coverity tool.

modules/video/test/test_tvl1optflow.cpp

@@ -52,12 +52,13 @@ namespace
 {
     // first four bytes, should be the same in little endian
     const float FLO_TAG_FLOAT = 202021.25f;  // check for this when READING the file
-    const char FLO_TAG_STRING[] = "PIEH";    // use this when WRITING the file
 
+#ifdef DUMP
     // binary file format for flow data specified here:
     // http://vision.middlebury.edu/flow/data/
     void writeOpticalFlowToFile(const Mat_<Point2f>& flow, const string& fileName)
     {
+        const char FLO_TAG_STRING[] = "PIEH";    // use this when WRITING the file
         ofstream file(fileName.c_str(), ios_base::binary);
 
         file << FLO_TAG_STRING;
@@ -76,6 +77,7 @@ namespace
             }
         }
     }
+#endif
 
     // binary file format for flow data specified here:
     // http://vision.middlebury.edu/flow/data/