RFR: 8284444: Sting typo

[Daniel Jeliński]

This patch adds missing `r` in `string`s

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Commit messages:
 - Fix sting typo

Changes: https://git.openjdk.java.net/jdk/pull/8125/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=8125&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8284444
  Stats: 25 lines in 8 files changed: 0 ins; 0 del; 25 mod
  Patch: https://git.openjdk.java.net/jdk/pull/8125.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/8125/head:pull/8125

PR: https://git.openjdk.java.net/jdk/pull/8125