add format indicator to get LOG_X warnings

The LOG_X macros emit a lot of warnings when compiling with the T
because they call the function logRecord (or logRecord_mt)
which has not been "marked" as calling printf, so gcc won't
emit typical printf warnings.

With the T, they directly translate to sprintf, so those warnings
pop up, much more verbose due to several macro expansions.

Let's make them pop up all the time so it's easier to fix them.

openair2/UTIL/LOG/log_if.h

@@ -60,8 +60,8 @@ extern "C" {
 //public_log_if( log_t *g_log;)
 
 public_log_if( int logInit (void);)
-public_log_if( void logRecord_mt(const char *file, const char *func, int line,int comp, int level, const char *format, ...);)
-public_log_if( void logRecord(const char *file, const char *func, int line,int comp, int level, const char *format, ...);)
+public_log_if( void logRecord_mt(const char *file, const char *func, int line,int comp, int level, const char *format, ...) __attribute__ ((format (printf, 6, 7)));)
+public_log_if( void logRecord(const char *file, const char *func, int line,int comp, int level, const char *format, ...) __attribute__ ((format (printf, 6, 7)));)
 public_log_if( int set_comp_log(int component, int level, int verbosity, int interval);)
 public_log_if( int  set_log(int component, int level, int interval);)
 public_log_if( void set_glog(int level, int verbosity);)