- Don't free mbuf, passed to interface output method if the latter

returns error. In this case mbuf has already been freed. [1]
- Remove redundant declaration.

PR:		kern/78893 [1]
Submitted by:	Liang Yi [1]
Reviewed by:	sam
MFC after:	1 day

sys/netinet/ip_fastfwd.c

@@ -594,9 +594,8 @@ ip_fastforward(struct mbuf *m)
 			} while ((m = m0) != NULL);
 			if (error) {
 				/* Reclaim remaining fragments */
-				for (; m; m = m0) {
+				for (m = m0; m; m = m0) {
 					m0 = m->m_nextpkt;
-					m->m_nextpkt = NULL;
 					m_freem(m);
 				}
 			} else