tools lib traceevent: Fix warning on '>=' operator

Although the '>=' (and '<=') operator is handled properly in
libtraceevent, it emitted following spurious warnings on perf test:

 $ perf test
 5: parse events tests                                     :
  ...
  Warning: unknown op '>='
  Warning: unknown op '>='
  Warning: unknown op '>='
  Warning: unknown op '>='
  Warning: unknown op '>='
  Warning: unknown op '>='
  ...

Add the operator to the checks.

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/1358236939-17393-1-git-send-email-namhyung@kernel.org


Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>