Fix format-truncation warnings

The following warnings are being addressed.

- hbsUtil.cpp: The correct value for MAX_ENTRY_STR_LEN should be 13
  this considering that values can be higher than 9999, the final space
  and the leading '\n'.
- hwmonAlarm.cpp: As a result of a discussion with Eric Macdonald, he
  suggested to remove the entire case for FM_ALARM_STATE_CLEAR as the
  reason buffer is not used and thus, there's no need to store a string there.
- pmonHdlr.cpp: A truncation warning was shown due to a possible usage of a
  unitialize buffer. The fix here is check by NULL.

Change-Id: I3c80cce99b2f521f8c7a9de4ce2b6036960dfaf6
Signed-off-by: Erich Cordoba <erich.cordoba.malibran@intel.com>

mtce/src/heartbeat/hbsUtil.cpp

@@ -163,7 +163,7 @@ void hbs_cluster_log ( string & hostname,
         if ( cluster.history[h].entries == MTCE_HBS_HISTORY_ENTRIES )
         {
 #define MAX_CLUSTER_LINE_LEN 100
-#define MAX_ENTRY_STR_LEN     10 /* "9999:9999 " */
+#define MAX_ENTRY_STR_LEN     13 /* "9999:9999 " */
             mtce_hbs_cluster_entry_type e = { 0, 0 } ;
             char str[MAX_CLUSTER_LINE_LEN] ;
             string line  = "";

mtce/src/hwmon/hwmonAlarm.cpp

@@ -257,15 +257,7 @@ int hwmon_alarm_util ( string           & hostname,
                              "%s is reporting a '%s' out-of-tolerance reading from the '%s' sensor",
                              hostname.c_str(), _getSev_str (severity).c_str(), sub_entity.c_str());
 
-            if ( state == FM_ALARM_STATE_CLEAR )
-            {
-                snprintf(alarm.reason_text, FM_MAX_BUFFER_LENGTH,
-                             "%s:%s alarm clear\n",
-                              alarm.alarm_id,
-                              alarm.entity_instance_id);
-                hostname_prefix_in_reason = false ;
-            }
-            else if ( state == FM_ALARM_STATE_MSG )
+            if ( state == FM_ALARM_STATE_MSG )
             {
                 if ( severity == FM_ALARM_SEVERITY_WARNING )
                 {

mtce/src/pmon/pmonHdlr.cpp

@@ -538,6 +538,11 @@ bool service_file_exists ( string service_filename,
                            char * path_n_name_ptr,
                            int    max_len )
 {
+    if ( path_n_name_ptr == NULL ) {
+        slog ("Path for service files search is null.\n");
+        return false;
+    }
+
     /* load the name of the service file */
     snprintf ( path_n_name_ptr, max_len, "%s/%s",
                                           SYSTEMD_SERVICE_FILE_DIR1,