tools lib traceevent: Cleanup realloc use

The if branch is completely unnecessary since 'realloc' can handle
NULL pointers for the first parameter.

This patch is just an adoption of Ulrich Drepper's recent patch on
perf tools.

Signed-off-by: Namhyung Kim <namhyung.kim@lge.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ulrich Drepper <drepper@gmail.com>
Link: http://lkml.kernel.org/r/1335230984-7613-1-git-send-email-namhyung.kim@lge.com
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>

tools/lib/traceevent/event-parse.c

@@ -633,12 +633,8 @@ static void add_event(struct pevent *pevent, struct event_format *event)
 {
 	int i;
 
-	if (!pevent->events)
-		pevent->events = malloc_or_die(sizeof(event));
-	else
-		pevent->events =
-			realloc(pevent->events, sizeof(event) *
-				(pevent->nr_events + 1));
+	pevent->events = realloc(pevent->events, sizeof(event) *
+				 (pevent->nr_events + 1));
 	if (!pevent->events)
 		die("Can not allocate events");
 

tools/lib/traceevent/parse-filter.c

@@ -148,17 +148,11 @@ add_filter_type(struct event_filter *filter, int id)
 	if (filter_type)
 		return filter_type;
 
-	if (!filter->filters)
-		filter->event_filters =
-			malloc_or_die(sizeof(*filter->event_filters));
-	else {
-		filter->event_filters =
-			realloc(filter->event_filters,
-				sizeof(*filter->event_filters) *
-				(filter->filters + 1));
-		if (!filter->event_filters)
-			die("Could not allocate filter");
-	}
+	filter->event_filters =	realloc(filter->event_filters,
+					sizeof(*filter->event_filters) *
+					(filter->filters + 1));
+	if (!filter->event_filters)
+		die("Could not allocate filter");
 
 	for (i = 0; i < filter->filters; i++) {
 		if (filter->event_filters[i].event_id > id)
@@ -1480,7 +1474,7 @@ void pevent_filter_clear_trivial(struct event_filter *filter,
 {
 	struct filter_type *filter_type;
 	int count = 0;
-	int *ids;
+	int *ids = NULL;
 	int i;
 
 	if (!filter->filters)
@@ -1504,10 +1498,8 @@ void pevent_filter_clear_trivial(struct event_filter *filter,
 		default:
 			break;
 		}
-		if (count)
-			ids = realloc(ids, sizeof(*ids) * (count + 1));
-		else
-			ids = malloc(sizeof(*ids));
+
+		ids = realloc(ids, sizeof(*ids) * (count + 1));
 		if (!ids)
 			die("Can't allocate ids");
 		ids[count++] = filter_type->event_id;