acl-plugin: hash lookup bitmask not cleared when ACL is unapplied from interface...

acl-plugin: hash lookup bitmask not cleared when ACL is unapplied from interface (VPP-935)

The logic in hash ACL bitmask update was using the vector
of ACLs applied to the interface to rebuild the hash lookup mask.
However, in transient cases (like doing group manipulation with
hash ACLs), that will not hold true. Thus, make
a local copy of for which ACL indices the hash_acl_apply
was called previously, and maintain that one local
to the hash_lookup.c file logic.

Change-Id: I30187d68febce8bba2ab6ffbb1eee13b5c96a44b
Signed-off-by: Andrew Yourtchenko <ayourtch@gmail.com>