perf_counter tools: Work around warnings in older GCCs

GCC 4.1.2 produces:

 util/parse-options.c: In function ‘get_value’:
 util/parse-options.c:36: warning: ‘arg’ may be used uninitialized in this function

 builtin-top.c: In function ‘display_thread’:
 builtin-top.c:178: warning: ‘printed’ may be used uninitialized in this function

Annotate them away by initializing these variables to 0.

Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
LKML-Reference: <new-submission>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Documentation/perf_counter/builtin-top.c

@@ -175,7 +175,7 @@ static void rb_insert_active_sym(struct rb_root *tree, struct sym_entry *se)
 
 static void print_sym_table(void)
 {
-	int printed, j;
+	int printed = 0, j;
 	int counter;
 	float events_per_sec = events/delay_secs;
 	float kevents_per_sec = (events-userspace_events)/delay_secs;

Documentation/perf_counter/util/parse-options.c

@@ -33,7 +33,7 @@ static int get_arg(struct parse_opt_ctx_t *p, const struct option *opt,
 static int get_value(struct parse_opt_ctx_t *p,
 		     const struct option *opt, int flags)
 {
-	const char *s, *arg;
+	const char *s, *arg = NULL;
 	const int unset = flags & OPT_UNSET;
 
 	if (unset && p->opt)