trace-cmd: add global functions for live tracing

We need a few functions to disable/enable tracing as well as add events to be
enabled on the first instance, this patch turns a couple of these local
functions into library functions.  Thanks,

Link: http://lkml.kernel.org/r/1448053053-24188-5-git-send-email-jbacik@fb.com

Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2 files changed