ZTS: zfs_mount_all_fail leaves /var/tmp/testrootPIDNUM directory around

[tsoome]

Before we can remove test files, we need to unmount datasets used by test first.

See also: zfs_mount_all_mountpoints.ksh

Motivation and Context

Clean up left over files from zfstest.

Description

unmount datasets from test then clean up mountpoints.

How Has This Been Tested?

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)
• 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]

Seems to make sense. I am just not sure about the irrelevant part about fscount. Right or not, but most of other tests I quickly checked use $ there also.

[behlendorf]

Makes sense. In ksh the "$" is optional within "(( ))" so either way should be fine.