synch: move held-lock-stack-is-not-empty assertion closer to its user
synch: move held-lock-stack-is-not-empty assertion closer to its user

This makes last_acquired_lock useable in subsequent commits.

Signed-off-by: Josef 'Jeff' Sipek <a620f141433c70aa9e43778305a6c68cbfadfb25@josefsipek.net>

jeffpc/libjeffpc,jeffpc/libjeffpc,jeffpc/libjeffpc,jeffpc/libjeffpc