Merge pull request #42883 from majianpeng/pwl-ssd-calc-allocated-bug

librbd/cache/pwl: fix m_bytes_{allocated,cached} calculation on reopen

Reviewed-by: Yin Congmin <congmin.yin@intel.com>
Reviewed-by: Ilya Dryomov <idryomov@gmail.com>

diff --cc src/librbd/cache/pwl/AbstractWriteLog.cc
Simple merge