perf annotate stdio: Set enough columns for --show-total-period

Now that we set the first column header according to wether
--show-total-period is being used, we need to size it accordingly.

Based-on-a-patch-by: Taeung Song <treeze.taeung@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Milian Wolff <milian.wolff@kdab.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: http://lkml.kernel.org/n/tip-pu504ffnit4m334k09hxcbs3@git.kernel.org


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