Windows: fix libafscp build directory

NTMakefile specifed the directory as libacl not libafscp

Change-Id: I12af68a19155d0764967f9cd2e8eb2d8795530d5
Reviewed-on: http://gerrit.openafs.org/10299
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Jeffrey Altman <jaltman@your-file-system.com>