RFR: CODETOOLS-7903000: JMH: Fix error message for @Setup helpers on a class missing @State

[Ian Kerins]

Such error messages previously incorrectly referred to `@TearDown`.

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Commit messages:
 - Fix error message for @Setup helpers on a class missing @State

Changes: https://git.openjdk.java.net/jmh/pull/44/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jmh&pr=44&range=00
  Issue: https://bugs.openjdk.java.net/browse/CODETOOLS-7903000
  Stats: 1 line in 1 file changed: 0 ins; 0 del; 1 mod
  Patch: https://git.openjdk.java.net/jmh/pull/44.diff
  Fetch: git fetch https://git.openjdk.java.net/jmh pull/44/head:pull/44

PR: https://git.openjdk.java.net/jmh/pull/44