Help compiller optimize out abd_verify().

[amotin]

While abd_verify() does nothing when built without debug, compiler
can't optimize it out by itself due to calls to external list_*()
and abd_verify_scatter(). This commit makes it explicit.

Types of changes

• 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)
• Library ABI change (libzfs, libzfs_core, libnvpair, libuutil and libzfsbootenv)
• Documentation (a change to man pages or other documentation)

Checklist:

• My code follows the OpenZFS code style requirements.
• I have updated the documentation accordingly.
• I have read the contributing document.
• I have added tests to cover my changes.
• I have run the ZFS Test Suite with this change applied.
• All commit messages are properly formatted and contain Signed-off-by.

[amotin]

Or should I use "#ifdef ZFS_DEBUG" instead?

[behlendorf]

Yes, it'd be better to use ZFS_DEBUG for this since that's how this is handled elsewhere in the code.

[amotin]

OK. Changed. I am curios why asserts still depend on NDEBUG, not ZFS_DEBUG as everything else.

[ikozhukhov]

LGTM
i can't use github feature for 'approve' - i have no review button for my account

[behlendorf]

I am curios why asserts still depend on NDEBUG, not ZFS_DEBUG as everything else.

I believe it's something we've just never gotten around to updating since it hasn't been a problem in practice. We probably should make it consistent at some point.