ena: Bump driver version to v2.8.1

[akiyano_amazon.com]

Summary

Changes since 2.8.0:

Bug Fixes:

• Fix LLQ normal width misconfiguration
• Check for errors when detaching children first, not last

Minor Changes:

• Remove \n from sysctl description

Approved by: cperciva (mentor)
MFC after: 3 days
Sponsored by: Amazon, Inc.

[cperciva]

I'd suggest s/update/bump/ in the first line, and then adding "since 2.8.0" when listing the changes in order to avoid confusion -- otherwise you're likely to get at least one email asking "did you forget to commit the updates".

[akiyano_amazon.com]

Fixed comments by cperciva@ I got via mail, since I accidentally turned comments off here:

I'd suggest s/update/bump/ in the first line, and then adding "since 2.8.0" when listing the changes in order to avoid confusion -- otherwise you're likely to get at least one email asking "did you forget to commit the updates".