pf: remove PF_TAG_GENERATED

It's never set, so we can remove both the check for it and the
definition.

Reviewed by:	mjg, glebius
Pointed out by:	markj
Sponsored by:	Rubicon Communications, LLC ("Netgate")
Differential Revision:	https://reviews.freebsd.org/D33814

sys/netpfil/pf/pf.c

@@ -6965,9 +6965,6 @@ pf_test6(int dir, int pflags, struct ifnet *ifp, struct mbuf **m0, struct inpcb
 	memset(&pd, 0, sizeof(pd));
 	pd.pf_mtag = pf_find_mtag(m);
 
-	if (pd.pf_mtag && pd.pf_mtag->flags & PF_TAG_GENERATED)
-		return (PF_PASS);
-
 	kif = (struct pfi_kkif *)ifp->if_pf_kif;
 	if (kif == NULL) {
 		DPFPRINTF(PF_DEBUG_URGENT,

sys/netpfil/pf/pf_mtag.h

@@ -36,7 +36,7 @@
 
 #ifdef _KERNEL
 
-#define	PF_TAG_GENERATED		0x01
+/*					0x01 unused. */
 #define	PF_TAG_DUMMYNET			0x02
 #define	PF_TAG_TRANSLATE_LOCALHOST	0x04
 #define	PF_PACKET_LOOPED		0x08