buildstats-summary: round the floating point percentage
This was rounded in python 2, but python 3 changed the default behavior of /.
We could switch to the same behavior as previous by switching to // rather
than /, but there's value in keeping at least one decimal point, to avoid the
misleading case where it says 0% but the reuse is non-zero.
Signed-off-by: Christopher Larson <chris_larson@mentor.com> Signed-off-by: Ross Burton <ross.burton@intel.com>
