Update LOG_WINDOW format params.

Params of size_t use %zu formatting, while int64_t use PRId64. These
params had not been updated in a while since LOG_WINDOW is a no-op
macro when LOG_NDEBUG is off.

Test: Enable LOG_NDEBUG and do make
Change-Id: I59e9fa1aa343fd0a1da83c40fd24f3ef7bae5ed4