libtraceevent: Man pages fix, rename tep_ref_get() to tep_get_ref()

The tep_ref_get() was renamed to tep_get_ref(), to be more consistent
with the other tep_ref_* APIs. However, in the man pages the API is
still with the old name. The documentation is fixed to reflect the
actual name of the API.

Signed-off-by: Tzvetomir Stoyanov (VMware) <tz.stoyanov@gmail.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Tzvetomir Stoyanov (VMware) <tz.stoyanov@gmail.com>
Cc: linux-trace-devel@vger.kernel.org
Link: http://lore.kernel.org/linux-trace-devel/20190808113636.13299-2-tz.stoyanov@gmail.com
Link: http://lore.kernel.org/lkml/20190919212541.697034573@goodmis.org


Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>