afs: Free 'addrs' array

afs: Free 'addrs' array

Currently, 3 places in libafs allocate an 'addrs' array in a very
similar way to loop through our list of servers:
ForceAllNewConnections(), afs_LoopServers(), and PCallBackAddr(). Of
these, only afs_LoopServers actually frees the array.
ForceAllNewConnections and PCallBackAddr leak the memory, but these
are only hit from infrequent pioctls that can only be run by root, so
the impact is small.

Fix ForceAllNewConnections and PCallBackAddr to free the array.

Change-Id: Ic348e29cefa7c41cbcb30f738f943e8d022a97f0
Reviewed-on: https://gerrit.openafs.org/13355
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Benjamin Kaduk <kaduk@mit.edu>