RFR: 8254722: bsd_zero builds broken after JDK-8253717

[Jie Fu]

This bug was found while I'm working on JDK-8253970 [1].
JDK-8253717 updated linux_zero but forgot bsd_zero.

[1] https://github.com/openjdk/jdk/pull/496#issuecomment-708088798

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Commit messages:
 - 8254722: bsd_zero builds broken after JDK-8253717

Changes: https://git.openjdk.java.net/jdk/pull/646/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=646&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8254722
  Stats: 5 lines in 1 file changed: 1 ins; 0 del; 4 mod
  Patch: https://git.openjdk.java.net/jdk/pull/646.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/646/head:pull/646

PR: https://git.openjdk.java.net/jdk/pull/646