BUG/MINOR: acls: Set the right refflag when patterns are loaded from a map

BUG/MINOR: acls: Set the right refflag when patterns are loaded from a map

For an ACL, we can load patterns from a map using the flag -M. For example:

    acl test hdr(host) -M -f hosts.map

The file is parsed as a map et the ACL will be executed as expected. But the
reference flag is wrong. It is set to PAT_REF_ACL. So the map will never be
listed by a "show map" on the stat socket. Setting the reference flag to
PAT_REF_ACL|PAT_REF_MAP fixes the bug.