Remove duplicate dedup_legacy_create test in common.run

[rrevans]

Motivation and Context

common.run lists tests/functional/dedup/dedup_legacy_create twice for unknown reasons:

zfs/tests/runfiles/common.run

Lines 679 to 682 in 50cbb14

	[tests/functional/dedup]
	tests = ['dedup_legacy_create', 'dedup_fdt_create', 'dedup_fdt_import',
	'dedup_legacy_create', 'dedup_legacy_import', 'dedup_legacy_fdt_upgrade',
	'dedup_legacy_fdt_mixed', 'dedup_quota']

This is detected by my experimental tooling that runs ZTS in parallel distributed to local VMs. It reports a warning if it observes the same test outcome twice. Turns out in this case the test is in the runfile twice.

I'm not 100% sure it should appear only once, but it seems odd that it's there twice. @allanjude is this a typo from c7ada64?

Description

Remove the duplicate test

How Has This Been Tested?

Ran the common.run suite

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.

[behlendorf]

Sure looks like a typo. There's no need to run this test multiple times.