Fix output file creation in streaming_onlineliblinear_sparse examples

there's absolutely no need for creating and opening the output
file prior writing into it in case of WIN32

examples/undocumented/libshogun/streaming_onlineliblinear_sparse.cpp

@@ -35,17 +35,16 @@ int main(int argc, char* argv[])
     float64_t C = 1.0;
     char *train_file_name = (char*)"../data/train_sparsereal.light";
     char *test_file_name = (char*)"../data/test_sparsereal.light";
-    char filename_tmp[] = "test_sparsereal.light.labels.XXXXXX";
+    char filename_tmp[] = "test_labels.XXXXXX";
 #ifdef _WIN32
     int err = _mktemp_s(filename_tmp, strlen(filename_tmp)+1);
     ASSERT(err == 0);
-    int fd = open(filename_tmp, O_CREAT|O_RDWR);
 #else
     int fd = mkstemp(filename_tmp);
-#endif
     ASSERT(fd != -1);
     int retval = close(fd);
     ASSERT(retval != -1);
+#endif
     char *test_labels_file_name = filename_tmp;
 
     if (argc > 4) {