Fix package build

[ctuffli]

Fixes for building packages. I introduced these errors in an earlier commit.

Motivation and Context

CI doesn't work if packages won't build

Description

How Has This Been Tested?

Built .deb packages on an Ubuntu 18.04 x86_64 system

Types of changes

• [x] Bug fix (non-breaking change which fixes an issue)
• [ ] New feature (non-breaking change which adds functionality)
• [ ] Performance enhancement (non-breaking change which improves efficiency)
• [ ] Code cleanup (non-breaking change which makes code smaller or more readable)
• [ ] Breaking change (fix or feature that would cause existing functionality to change)
• [ ] Documentation (a change to man pages or other documentation)

Checklist:

• [x] My code follows the ZFS on Linux code style requirements.
• [ ] I have updated the documentation accordingly.
• [x] I have read the contributing document.
• [ ] I have added tests to cover my changes.
• [ ] All new and existing tests passed.
• [x] All commit messages are properly formatted and contain Signed-off-by.

[ghost]

@ctuffli Can you make this against the projects/pr-rebase branch? We have been developing on that branch so we don't break stuff on the main branch as we quickly iterate, and as a result projects/zfsbsd is a fair bit behind. For example I have solved the sed issues over there already. Thanks!

[ghost]

@ctuffli I applied the module/zfs/Makefile.in fix to projects/pr-rebase manually, because I had hacked around that already there so I had to put things back first.

The problem we're facing now is that while the packages do build, they do not have all the pieces there. spl.ko is curiously absent and its symbols are missing.

[ghost]

Please open a PR against projects/pr-rebase if you are able to make progress with the packaging issue. Thanks for the help!