revert: mds: provide a mechanism to authpin while freezing

revert: mds: provide a mechanism to authpin while freezing

This is a functional revert of a9964a7ccc4394f923fb0f1c76eb8fa03fe8733d
git revert was giving too many conflicts, as the code has changed
too much since the original commit.

The bypass freezing mechanism lead us into several deadlocks,
and when we found out that a freezing inode defers reclaiming
client caps, we realized that we needed to try a different approach.
This commit removes the bypass freezing related changes to clear way
for a different approach to resolving the conflict between quiesce
and freezing.

Signed-off-by: Leonid Usov <leonid.usov@ibm.com>