tools lib traceevent: Man pages for event filter APIs

tools lib traceevent: Man pages for event filter APIs

Added new man pages, describing libtraceevent event filter APIs:

  tep_filter_alloc()
  tep_filter_free()
  tep_filter_reset()
  tep_filter_add_filter_str()
  tep_filter_strerror()
  tep_event_filtered()
  tep_filter_remove_event()
  tep_filter_match()
  tep_filter_copy()
  tep_filter_compare()
  tep_filter_make_string()

Signed-off-by: Tzvetomir Stoyanov <tstoyanov@vmware.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: linux-trace-devel@vger.kernel.org
Link: http://lore.kernel.org/linux-trace-devel/20190503091119.23399-23-tstoyanov@vmware.com
Link: http://lkml.kernel.org/r/20190510200109.638838141@goodmis.org
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>