kernelshark: Have capture "Run" button also be "Stop" button
kernelshark: Have capture "Run" button also be "Stop" button

Instead of popping up another dialog to stop the run, have
the "Run" button simply change to "Stop". This makes it a lot nicer.

Signed-off-by: Steven Rostedt <43232e92d70cc7aa53504ad0397085ee47bad87f@goodmis.org>

bigzz/trace-cmd,bigzz/trace-cmd