RFR: Memory leak fix

[Prasanta Sadhukhan]

Memory leak fix for couple of strings.

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Commit messages:
 - Memory leak fix

Changes: https://git.openjdk.java.net/lanai/pull/182/files
 Webrev: https://webrevs.openjdk.java.net/?repo=lanai&pr=182&range=00
  Stats: 6 lines in 1 file changed: 4 ins; 0 del; 2 mod
  Patch: https://git.openjdk.java.net/lanai/pull/182.diff
  Fetch: git fetch https://git.openjdk.java.net/lanai pull/182/head:pull/182

PR: https://git.openjdk.java.net/lanai/pull/182