Comment out missing comerr functions from afsauthent.def

Comment out missing comerr functions from afsauthent.def

Apparently commit 70c4922980d1596155b4021cd72d6895c2371e23 was overzealous
in making Windows match Unix, as these functions are not available
in the Windows build.

Reviewed-on: https://gerrit.openafs.org/13219
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Benjamin Kaduk <kaduk@mit.edu>
(cherry picked from commit 9d0b2698ac7ab8bb689f30d819bbef08c05a8bf7)

Change-Id: I6ea04a04a2e18f3a8b7f2fdd0e2ca49f4b208361
Reviewed-on: https://gerrit.openafs.org/13222
Reviewed-by: Benjamin Kaduk <kaduk@mit.edu>
Tested-by: BuildBot <buildbot@rampaginggeek.com>