Integrated: 8253260: Fix whitespace errors in .m and .metal files in lanai repo

[Kevin Rushforth]

Fix whitespace errors in a few `.m` files and the one `.metal` file that had trailing whitespace. This is needed
because we will enable jcheck to check for whitespace once the next merge from jdk is complete.

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Commit messages:
 - 8253260: Fix whitespace errors in .m and .metal files in lanai repo

Changes: https://git.openjdk.java.net/lanai/pull/100/files
 Webrev: https://webrevs.openjdk.java.net/?repo=lanai&pr=100&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8253260
  Stats: 7 lines in 5 files changed: 0 ins; 0 del; 7 mod
  Patch: https://git.openjdk.java.net/lanai/pull/100.diff
  Fetch: git fetch https://git.openjdk.java.net/lanai pull/100/head:pull/100

PR: https://git.openjdk.java.net/lanai/pull/100