[Rev 03] RFR: 8241476: Linux build warnings issued on gcc 9

[Thiago Milczarek Sayao]

> Simple fix to remove annoying warnings.

Thiago Milczarek Sayao has updated the pull request incrementally with one additional commit since the last revision:

  Gstreamer build

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Changes:
  - all: https://git.openjdk.java.net/jfx/pull/150/files
  - new: https://git.openjdk.java.net/jfx/pull/150/files/67adeaee..92f1b9ab

Webrevs:
 - full: https://webrevs.openjdk.java.net/jfx/150/webrev.03
 - incr: https://webrevs.openjdk.java.net/jfx/150/webrev.02-03

  Stats: 1 line in 1 file changed: 0 ins; 1 del; 0 mod
  Patch: https://git.openjdk.java.net/jfx/pull/150.diff
  Fetch: git fetch https://git.openjdk.java.net/jfx pull/150/head:pull/150

PR: https://git.openjdk.java.net/jfx/pull/150