app-arch/zstd: fix automagic dep on app-arch/lz4

[ktrace]

Add USE "lz4" for build with or without app-arch/lz4.
Add conditional DEPENDS/RDEPENDS.
Add USE "lz4" in metadata.

Bug: https://bugs.gentoo.org/show_bug.cgi?id=656316
Closes: #8548
Package-Manager: Portage-2.3.24, Repoman-2.3.6

[gentoo-bot]

Pull Request assignment

Areas affected: ebuilds
Packages affected: app-arch/zstd

app-arch/zstd: patrick

At least one of the listed packages is maintained entirely by non-GitHub developers!

Bugs linked: 656316

In order to force reassignment and/or bug reference scan, please append [please reassign] to the pull request title.

[gentoo-repo-qa-bot]

Pull request CI report

Report generated at: 2018-05-26 17:10 UTC
Newest commit scanned: d5ac26f
Status: ✅ good

No issues found

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