* ldap.cc (rediscover_thread): Remove.

(cyg_ldap::open): Remove code to rediscover DC.  It just won't do the
	right thing.
	(cyg_ldap::enumerate_ad_accounts): Change to be self-sufficient (no
	explicit open call required).  Enumerate on a DC of the domain itself
	instead of relying on delegation.  Remove ill-advised code trying to
	generate rootdse from domain name.
	* passwd.cc (pg_ent::enumerate_ad): Drop explicit call to
	cyg_ldap::open.

winsup/cygwin/passwd.cc

@@ -566,8 +566,6 @@ pg_ent::enumerate_ad ()
 
 	  if (!resume)
 	    {
-	      if (!cldap.open (NULL))
-		return NULL;
 	      ++resume;
 	      if (!nss_db_enum_primary ()
 		  || !cldap.enumerate_ad_accounts (NULL, group))