Remove global trace_handle
Remove global trace_handle

The trace_handel was used as a work around for the function graph
tracer needing to reference a handel. This has been fixed, and the
global trace_handle is no longer needed.

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

bigzz/trace-cmd,bigzz/trace-cmd