Don't use wrong weight when passivating group

[pcd1193182]

Sponsored by: Klara, Inc.; Wasabi Technology, Inc.

Motivation and Context

When we're passivating a metaslab group in ZFS, we start by passivating the metaslabs that have been activated for each of the allocators. To do that, we need to provide a weight. However, currently this erroneously always uses a segment-based weight, even if segment-based weighting is disabled.

Description

Use the normal weight function, which will decide which type of weight to use.

How Has This Been Tested?

Basic sanity testing, plus tests where I verified that on unload, the metaslab weights were space-based instead of segment-based when segment-based was disabled.

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)
• Quality assurance (non-breaking change which makes the code more robust against bugs)
• 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.