perf hists/tui: Count callchain rows separately

When TUI hist browser expands/collapses callchains it accounted number
of callchain nodes into total entries to show.  However this code
ignores filtering so that it can make the cursor go to out of screen.

Thanks to Jiri Olsa for pointing out a bug (and a fix) in the code.

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Link: http://lkml.kernel.org/r/1398327843-31845-12-git-send-email-namhyung@kernel.org


Signed-off-by: Jiri Olsa <jolsa@kernel.org>