perf ui/tui: Fix off-by-one in hist_browser__update_nr_entries()

perf ui/tui: Fix off-by-one in hist_browser__update_nr_entries()

The nr_entries variable is increased inside the loop in the function
but it always count the first entry regardless of it's filtered or
not; caused an off-by-one error.

It'd become a problem especially there's no entry at all - it'd get a
segfault during referencing a NULL pointer.

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Link: http://lkml.kernel.org/r/1398327843-31845-9-git-send-email-namhyung@kernel.org
Signed-off-by: Jiri Olsa <jolsa@kernel.org>