* f2b_logfile_close() : safer version

src/logfile.c

@@ -41,8 +41,12 @@ f2b_logfile_open(f2b_logfile_t *file, const char *path) {
 void
 f2b_logfile_close(f2b_logfile_t *file) {
   assert(file != NULL);
+
+  if (file->fd)
     fclose(file->fd);
+
   file->opened = false;
+  file->fd = NULL;
 }
 
 bool