Standardize inline and static declaration order.
Summary: Just readability patch. No semantic change. It seems like clang-format likes it better as well.
Test Plan:
make check
Reviewers: freetrader, #bitcoin_abc, CCulianu
Reviewed By: #bitcoin_abc, CCulianu
Subscribers: CCulianu
Differential Revision: https://reviews.bitcoinabc.org/D398