[jdk21u] RFR: 8309591: Socket.setOption(TCP_QUICKACK) uses wrong level

[Aleksey Shipilev]

Clean backport to fix TCP_QUICKACK bug.

Additional testing:
 - [ ] Linux AArch64 fastdebug, `jdk_net`
 - [ ] Linux AArch64 fastdebug, `tier1 tier2 tier3`

-------------

Commit messages:
 - Backport 56a73a6f0f3d38379cecea1de5eacb751febca95

Changes: https://git.openjdk.org/jdk21u/pull/57/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk21u&pr=57&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8309591
  Stats: 7 lines in 2 files changed: 0 ins; 0 del; 7 mod
  Patch: https://git.openjdk.org/jdk21u/pull/57.diff
  Fetch: git fetch https://git.openjdk.org/jdk21u.git pull/57/head:pull/57

PR: https://git.openjdk.org/jdk21u/pull/57