[lworld] RFR: 8378232: [lworld] Redundant clause in ClassFileParser::verify_legal_class_modifiers

[Casper Norrbin]

Hi everyone,

In `ClassFileParser::verify_legal_class_modifiers`, the `valid_value_class` bool had a redundant `!is_identity`. Since `is_identity` is already handled by short-circuiting earlier in the expression, that condition is always true in the remaining branch. This change removes the redundancy without changing behavior.

Testing:
- Tier 1

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Commit messages:
 - fix

Changes: https://git.openjdk.org/valhalla/pull/2146/files
  Webrev: https://webrevs.openjdk.org/?repo=valhalla&pr=2146&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8378232
  Stats: 2 lines in 1 file changed: 0 ins; 1 del; 1 mod
  Patch: https://git.openjdk.org/valhalla/pull/2146.diff
  Fetch: git fetch https://git.openjdk.org/valhalla.git pull/2146/head:pull/2146

PR: https://git.openjdk.org/valhalla/pull/2146