perf stat: Always correctly indent ratio column

When cycles or instructions do not print anything, as in being,
--per-socket or --per-core modi, the ratio column was not correctly
indented for them. This lead to some ratios not lining up with the
others. Always indent correctly when nothing is printed.

Signed-off-by: Andi Kleen <ak@linux.intel.com>
Link: http://lkml.kernel.org/r/1426087682-22765-3-git-send-email-andi@firstfloor.org


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