tools lib traceevent: Free filter tokens in process_filter()

valgrind showed that the filter token wasn't being freed properly in
process_filter().

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: http://lkml.kernel.org/r/20150324135923.817723903@goodmis.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/lib/traceevent/parse-filter.c

@@ -1058,6 +1058,7 @@ process_filter(struct event_format *event, struct filter_arg **parg,
 					*parg = current_op;
 				else
 					*parg = current_exp;
+				free(token);
 				return PEVENT_ERRNO__UNBALANCED_PAREN;
 			}
 			break;
@@ -1168,6 +1169,7 @@ process_filter(struct event_format *event, struct filter_arg **parg,
 
 	*parg = current_op;
 
+	free(token);
 	return 0;
 
  fail_alloc: