perf hist browser: Fix hierarchy column counts

The perf report/top on TUI supports horizontal scrolling using LEFT and
RIGHT keys.

But it calculate the number of columns incorrectly when hierarchy mode
is enabled so that keep pressing RIGHT key can make the output
disappeared.

In the hierarchy mode, all sort keys are collapsed into a single column,
so it needs to be applied when calculating column numbers.

Reported-and-Tested-by: Markus Trippelsdorf <markus@trippelsdorf.de>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20161024162110.17918-1-namhyung@kernel.org


Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>