perf trace: Don't use pager if scripting

It's useful for paging through raw traces, but just gets in the
way when scripting.

Signed-off-by: Tom Zanussi <tzanussi@gmail.com>
Cc: fweisbec@gmail.com
Cc: rostedt@goodmis.org
LKML-Reference: <1267599873-8193-3-git-send-email-tzanussi@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>