Support the --show-nr-samples in the TUI browser.

Committer notes:

Lift the restriction about --tui but leave it for --gtk:

  $ export LD_LIBRARY_PATH=~/lib64
  $ perf annotate --gtk --show-nr-samples --show-nr-samples is not available in --gtk mode at this time
  $
Signed-off-by: Taeung Song <treeze.taeung@gmail.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: http://lkml.kernel.org/r/1503046023-5646-1-git-send-email-treeze.taeung@gmail.comSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>