perf trace/scripting: Don't display 'scripting unsupported' msg unnecessarily

The 'scripting unsupported' message should only be displayed
when the -s or -g options are used, and not when they aren't, as
the current code does.

Signed-off-by: Tom Zanussi <tzanussi@gmail.com>
Cc: rostedt@goodmis.org
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <1260163919-6679-3-git-send-email-tzanussi@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>