tools lib traceevent: Removed unneeded !! and return parenthesis

As return is not a function we do not need parenthesis around the return
value. Also, a function returning bool does not need to add !!.

Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Tzvetomir Stoyanov <tstoyanov@vmware.com>
Link: http://lkml.kernel.org/r/20190401164343.817886725@goodmis.org


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