perf ui gtk: Add perf_gtk__show_helpline() for pr_*

Use helpline for printing error/debug messages. The code resembles a TUI
counter part and only print the first line of the message.

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Acked-by: Pekka Enberg <penberg@kernel.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1345104894-14205-5-git-send-email-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
diff --git a/tools/perf/ui/setup.c b/tools/perf/ui/setup.c
index 791fb15..c7820e5 100644
--- a/tools/perf/ui/setup.c
+++ b/tools/perf/ui/setup.c
@@ -1,7 +1,11 @@
+#include <pthread.h>
+
 #include "../cache.h"
 #include "../debug.h"
 
 
+pthread_mutex_t ui__lock = PTHREAD_MUTEX_INITIALIZER;
+
 void setup_browser(bool fallback_to_pager)
 {
 	if (!isatty(1) || dump_trace)