viced: move host tmay fields before index

viced: move host tmay fields before index

The index field and those after it in struct host do not get zeroed
when a host is reused.  The placement of the tmay fields after index
in commit 9a0a8ca4d186cf953b87d9fae1a35f66090b060c results in the
use of uninitialized memory.

This change moves the tmay fields before index which permits
the HOST_TO_ZERO() macro to compute the correct size to be memset()
to zero.

Change-Id: I1f93bebb23c99eaa7826dafa8cd7497d1b49bb53
Reviewed-on: http://gerrit.openafs.org/11286
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Jeffrey Altman <jaltman@your-file-system.com>
Reviewed-by: Benjamin Kaduk <kaduk@mit.edu>
Reviewed-by: D Brashear <shadow@your-file-system.com>