* lib/acl-internal.c: Remove struct stat parameter from HP-UX's version of
acl_nontrivial. Check if the acl has at most three entries instead (it must
have exactly three entries according to the HP-UX documentation). Ignore
uids and gids as long as an entry is either for a user (i.e., the owner),
a group (i.e., the owning group), or others.
* lib/acl-internal.h: Change HP-UX's acl_nontrivial prototype.
* lib/qcopy-acl.c (qcopy_acl): With that, we no longer need to stat the source
file.