afs: incorrect types for AFSDB IPv4 addresses

afs: incorrect types for AFSDB IPv4 addresses

DNS lookup results were being handled with int types.

Fortunately, this seems to be harmless, due to use of
memcpy when the types don't match, and assignment only
when both sides were int.

However, to avoid any future unpleasantness, change
them to afs_uint32.

No functional change should be incurred.

Change-Id: I31aeabb4ae3194a00b29a1fa767d05af167b4e4f
Reviewed-on: http://gerrit.openafs.org/12117
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Chas Williams <3chas3@gmail.com>
Reviewed-by: Benjamin Kaduk <kaduk@mit.edu>