zfs-mount-genrator: dependencies should be space-separated

[yshui]

Motivation and Context

zfs-mount-generator generates systemd unit for mounting zfs datasets. when the dataset is encrypted, it will generate a dependencies (Wants= and After= in systemd terms) to the corresponding load-key service

however, the generated string uses comma (,) as the separate of systemd units, while systemd actually expects spaces ( ). this cause the load-key service to not be run, and the dataset will fail to mount because it cannot be opened.

Description

when generating Wants= and Afters= strings, change the separate from comma to space.

How Has This Been Tested?

tested locally with encrypted datasets.

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)
• Documentation (a change to man pages or other documentation)

Checklist:

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

[behlendorf]

@aerusso would you mind reviewing this.

[aerusso]

We can just jump straight to the "6th stage of debugging": "How did that ever work?" LGTM

[rlaager]

This change is correct. Wants= is a space-separated list.