uipc_usrreq: revert addition of EMPTYPATH for bindat(2)

The caller wants the parent vnode, which cannot be provided for emptypath
lookups.

Reported and reviewed by:	markj
Fixes:	12c590a9ab ("bindat(2)/connectat(2): allow implicit EMPTYPATH for unix domain sockets")
Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
Differential revision:	https://reviews.freebsd.org/D57448

lib/libsys/open.2

@@ -447,11 +447,9 @@ The other functionality of the returned file descriptor is limited to
 the following descriptor-level operations:
 .Pp
 .Bl -tag -width __acl_aclcheck_fd -offset indent -compact
-.It Xr bindat 2
-for unix domain socket
-.Pq see Xr unix 4
 .It Xr connectat 2
 for unix domain socket
+.Pq see Xr unix 4
 .It Xr fcntl 2
 but advisory locking is not allowed
 .It Xr dup 2

sys/kern/uipc_usrreq.c

@@ -612,9 +612,8 @@ uipc_bindat(int fd, struct socket *so, struct sockaddr *nam, struct thread *td)
 	buf[namelen] = 0;
 
 restart:
-	NDINIT_ATRIGHTS(&nd, CREATE, NOFOLLOW | LOCKPARENT | NOCACHE |
-	    EMPTYPATH, UIO_SYSSPACE, buf, fd, cap_rights_init_one(&rights,
-	    CAP_BINDAT));
+	NDINIT_ATRIGHTS(&nd, CREATE, NOFOLLOW | LOCKPARENT | NOCACHE,
+	    UIO_SYSSPACE, buf, fd, cap_rights_init_one(&rights, CAP_BINDAT));
 /* SHOULD BE ABLE TO ADOPT EXISTING AND wakeup() ALA FIFO's */
 	error = namei(&nd);
 	if (error)