perf ui/tui: Print helpline message as is

When a tip message contains a percent sign, it was treated printf format
specifier so broken string was printed like below.

  Tip: Limit to show entries above 577nly: perf report --percent-limit 5
                                   ^^^

As ui_browser__show receives format string, pass additional "%s" so that
the help (tip) message can be printed as is.

  Tip: Limit to show entries above 5% only: perf report --percent-limit 5

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/r/1452509594-13616-1-git-send-email-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>