RFR: 8286394: Address possibly lossy conversions in jdk.naming.dns

[Darragh Clarke]

Added an int cast for the `timeoutLeft` assignment, looking through the code and other uses of the variable it seems to show no issues with lossy conversion. As part of this I removed the file to disable the conversion warning

I tested this build and it doesn't give any warnings on this file

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Commit messages:
 - added int cast and reenabled warning for lossy conversion

Changes: https://git.openjdk.org/jdk/pull/10607/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=10607&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8286394
  Stats: 2 lines in 2 files changed: 0 ins; 1 del; 1 mod
  Patch: https://git.openjdk.org/jdk/pull/10607.diff
  Fetch: git fetch https://git.openjdk.org/jdk pull/10607/head:pull/10607

PR: https://git.openjdk.org/jdk/pull/10607