perf tools: Fix pager on minimal-install embedded systems

Some Distributions may lack "less" package being included by default,
e.g., Linaro nano rootfs. In those cases use the portable "pager"
command instead of "less".
Signed-off-by: Avik Sil <avik.sil@linaro.org>
Acked-by: Ingo Molnar <mingo@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1338287725-26382-1-git-send-email-avik.sil@linaro.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/util/pager.c

@@ -57,6 +57,10 @@ void setup_pager(void)
 	}
 	if (!pager)
 		pager = getenv("PAGER");
+	if (!pager) {
+		if (!access("/usr/bin/pager", X_OK))
+			pager = "/usr/bin/pager";
+	}
 	if (!pager)
 		pager = "less";
 	else if (!*pager || !strcmp(pager, "cat"))