When locking key files for a zone, we iterate over all the views and
lock a mutex inside the zone structure. However, if we envounter an
in-view zone, we will try to lock the key files twice, one time for
the home view and one time for the in-view view. This will lead to
a deadlock because one thread is trying to get the same lock twice.
(cherry picked from commit 42c601ae14)
bb1f0404ab