tracing/filter: Add missing initialization

Add missing initialization for ret variable. Its initialization
is based on the re_cnt variable, which is being set deep down
in the ftrace_function_filter_re function.

I'm not sure compilers would be smart enough to see this in near
future, so killing the warning this way.

Link: http://lkml.kernel.org/r/1340120894-9465-2-git-send-email-jolsa@redhat.com

Signed-off-by: Jiri Olsa <jolsa@redhat.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

kernel/trace/trace_events_filter.c

@@ -2002,7 +2002,7 @@ static int ftrace_function_set_regexp(struct ftrace_ops *ops, int filter,
 static int __ftrace_function_set_filter(int filter, char *buf, int len,
  struct function_filter_data *data)
 {
- int i, re_cnt, ret;
+ int i, re_cnt, ret = -EINVAL;
  int *reset;
  char **re;