oeqa.buildperf: try harder when splitting 'nevr' string
Try to be more intelligent when splitting out recipe name, epoch,
version and revision from the buildstat directory name. Previous
assumption was that package versions never contain a dash but obviously
that is not necessarily true. The new assumption is that the package
version starts with a number.
Signed-off-by: Markus Lehtonen <markus.lehtonen@linux.intel.com> Signed-off-by: Ross Burton <ross.burton@intel.com>
