Windows: AFSRemoveCcb cannot fail

Since AFSRemoveCcb cannot fail, change the signature from returning
NTSTATUS to void.

Remove all error handling code.

Change-Id: Ifa893a714f97cefb9bd122ab84508e5d36987e88
Reviewed-on: http://gerrit.openafs.org/8851
Reviewed-by: Derrick Brashear <shadow@your-file-system.com>
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Jeffrey Altman <jaltman@your-file-system.com>
Tested-by: Jeffrey Altman <jaltman@your-file-system.com>