Bring the devkit makefiles closer to the naming convention used in the JDK build system by using uppercase variable names.
Testing: * Built devkit on linux-x64 * Verified that the JDK builds with the new devkit ------------- Commit messages: - 8369328: Use uppercase variable names in the devkit makefiles Changes: https://git.openjdk.org/jdk/pull/27679/files Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=27679&range=00 Issue: https://bugs.openjdk.org/browse/JDK-8369328 Stats: 98 lines in 2 files changed: 0 ins; 0 del; 98 mod Patch: https://git.openjdk.org/jdk/pull/27679.diff Fetch: git fetch https://git.openjdk.org/jdk.git pull/27679/head:pull/27679 PR: https://git.openjdk.org/jdk/pull/27679
