make TTimeStamp compile again on FreeBSD. Fixes issue 97341.

git-svn-id: http://root.cern.ch/svn/root/trunk@45957 27541ba8-7e3a-0410-8455-c3a389f83636

core/base/src/TTimeStamp.cxx

@@ -411,7 +411,18 @@ Int_t TTimeStamp::GetZoneOffset()
 #if defined(R__WINGCC)
    return _timezone;
 #else
+#if !defined(R__FBSD) && !defined(R__OBSD)
    return  timezone;   // unix has extern long int
+#else	 
+   time_t tp = 0;	 
+   time(&tp);	 
+#ifdef _REENTRANT	 
+   struct tm buf;	 
+   return -localtime_r(&tp, &buf)->tm_gmtoff;	 
+#else	 
+   return -localtime(&tp)->tm_gmtoff;	 
+#endif	 
+#endif  
 #endif
 #else
    _tzset();