perf tools: Introduce set_term_quiet_input helper function

Adding set_term_quiet_input helper to set the terminal quiet, out from
'perf top', used in following patches in 'perf kvm'.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jean Pihet <jean.pihet@linaro.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1407747014-18394-9-git-send-email-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
diff --git a/tools/perf/builtin-top.c b/tools/perf/builtin-top.c
index 10fc7e8..e8459e2 100644
--- a/tools/perf/builtin-top.c
+++ b/tools/perf/builtin-top.c
@@ -580,20 +580,14 @@
 static void *display_thread(void *arg)
 {
 	struct pollfd stdin_poll = { .fd = 0, .events = POLLIN };
-	struct termios tc, save;
+	struct termios save;
 	struct perf_top *top = arg;
 	int delay_msecs, c;
 
-	tcgetattr(0, &save);
-	tc = save;
-	tc.c_lflag &= ~(ICANON | ECHO);
-	tc.c_cc[VMIN] = 0;
-	tc.c_cc[VTIME] = 0;
-
 	pthread__unblock_sigwinch();
 repeat:
 	delay_msecs = top->delay_secs * 1000;
-	tcsetattr(0, TCSANOW, &tc);
+	set_term_quiet_input(&save);
 	/* trash return*/
 	getc(stdin);