perf hists browser: Fix column indentation on --hierarchy

When horizontall scrolling is used in hierarchy mode, the the right most
column has unnecessary indentation.  Actually it's needed only if some
of left (overhead) columns were shown.

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Tested-by: Markus Trippelsdorf <markus@trippelsdorf.de>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20161108130833.9263-4-namhyung@kernel.org


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