T tracer tools: fix memory leaks, clang warnings

- Fix memory leaks detected by ASan
- Initialize variables that are flagged by compiler
- C struct initializer: x:y needs to be .x=y

common/utils/T/tracer/textlog.c

@@ -86,7 +86,7 @@ int main(int n, char **v)
   int i;
   event_handler *h;
   logger *textlog;
-  gui *g;
+  gui *g = NULL;    /* initialization not necessary but gcc is not happy */
   int gui_mode = 0;
   view *out;
   int gui_active = 1;