HELPER/LOG: review unused symbols

Remove unused functions:
- log_catch
- log_rethrow
- log_try

Signed-off-by: Antonio Borneo <borneo.antonio@gmail.com>

src/helper/log.h

@@ -80,14 +80,6 @@ void kept_alive(void);
 void alive_sleep(uint64_t ms);
 void busy_sleep(uint64_t ms);
 
-/* log entries can be paused and replayed roughly according to the try/catch/rethrow
- * concepts in C++
- */
-void log_try(void);
-void log_catch(void);
-void log_rethrow(void);
-
-
 typedef void (*log_callback_fn)(void *priv, const char *file, unsigned line,
 		const char *function, const char *string);