perf ui browser: Fixup cleaning unused lines at the bottom

perf ui browser: Fixup cleaning unused lines at the bottom

Now that we can have extra title lines we should use ui_browser->rows
and not ->height when drawing lines, as well as adding
ui_browser->extra_title_lines to browser->y when cleaning unused lines
at the bottom, otherwise we end up clobbering with spaces the last line
just shown by ui_browser->refresh() routine.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jin Yao <yao.jin@linux.intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Fixes: ef9ff6017e3c ("perf ui browser: Move the extra title lines from the hists browser")
Link: https://lkml.kernel.org/n/tip-dfcpokt1pm5ixm8n9pxwtstz@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>