cve-check: include epoch in product version output

In the generated cve.log files, include the epoch in the product
version. This better matches how versions are displayed elsewhere,
in particular the bb.warn("Found unpatched CVE...") that appears
on the terminal when CVEs are found.

Signed-off-by: Ralph Siemsen <ralph.siemsen@linaro.org>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
(cherry picked from commit e1c3c0b6)
Signed-off-by: Steve Sakoman <steve@sakoman.com>