tools lib traceevent: Man pages for trace sequences APIs

Create man pages for trace sequences libtraceevent APIs:

  trace_seq_init(),
  trace_seq_destroy(),
  trace_seq_reset(),
  trace_seq_terminate(),
  trace_seq_putc(),
  trace_seq_puts(),
  trace_seq_printf(),
  trace_seq_vprintf(),
  trace_seq_do_fprintf(),
  trace_seq_do_printf()

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/20190503091119.23399-27-tstoyanov@vmware.com
Link: http://lkml.kernel.org/r/20190510200110.462646052@goodmis.org


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