trace-cmd: Move kernel_stack event handler to "function" plugin.

The "kernel_stack" event handler does not depend on any trace-cmd
context, it can be used aside from the application. The code is
moved to libtraceevent "function" plugin.

Link: http://lore.kernel.org/linux-trace-devel/20190726124308.18735-2-tz.stoyanov@gmail.com

Signed-off-by: Tzvetomir Stoyanov (VMware) <tz.stoyanov@gmail.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2 files changed