RFR: JDK-8296661 : Fix typo

[ScientificWare]

I suspect a typo in the documentation comments.

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Commit messages:
 - Fix typos in CSSParser.java

Changes: https://git.openjdk.org/jdk/pull/10975/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=10975&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8296661
  Stats: 1 line in 1 file changed: 0 ins; 0 del; 1 mod
  Patch: https://git.openjdk.org/jdk/pull/10975.diff
  Fetch: git fetch https://git.openjdk.org/jdk pull/10975/head:pull/10975

PR: https://git.openjdk.org/jdk/pull/10975