refactor: Fix unreachable code in init arg checks (part 2)
refactor: Fix unreachable code in init arg checks (part 2)

Summary:
Follow-up for rABC6c84fca7a26eee3f5f031f02610d4528f7ef8276
which lost the changes for an unknown reason.

Backport of core [[https://github.com/bitcoin/bitcoin/pull/19131 | PR19131]].

Test Plan:
With Werror enabled:
  ninja all check-all

Reviewers: #bitcoin_abc, jasonbcox

Reviewed By: #bitcoin_abc, jasonbcox

Differential Revision: https://reviews.bitcoinabc.org/D8658

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