Index: uipc_mbuf.c
===================================================================
RCS file: /cvs/src/sys/kern/uipc_mbuf.c,v
retrieving revision 1.224
diff -u -p -r1.224 uipc_mbuf.c
--- uipc_mbuf.c	15 Apr 2016 05:05:21 -0000	1.224
+++ uipc_mbuf.c	15 Apr 2016 05:19:49 -0000
@@ -326,8 +326,7 @@ m_clget(struct mbuf *m, int how, u_int p
 	}
 	buf = pool_get(pp, how == M_WAIT ? PR_WAITOK : PR_NOWAIT);
 	if (buf == NULL) {
-		if (m0)
-			m_freem(m0);
+		m_freem(m0);
 		return (NULL);
 	}
 
@@ -983,8 +982,7 @@ m_inject(struct mbuf *m0, int len0, int 
 
 	MGET(n, wait, MT_DATA);
 	if (n == NULL) {
-		if (n2)
-			m_freem(n2);
+		m_freem(n2);
 		return (NULL);
 	}
 
@@ -1399,15 +1397,10 @@ ml_dechain(struct mbuf_list *ml)
 unsigned int
 ml_purge(struct mbuf_list *ml)
 {
-	struct mbuf *m, *n;
 	unsigned int len;
 
-	for (m = ml->ml_head; m != NULL; m = n) {
-		n = m->m_nextpkt;
-		m_freem(m);
-	}
-
 	len = ml->ml_len;
+	m_purge(ml->ml_head);
 	ml_init(ml);
 
 	return (len);
@@ -1460,7 +1453,6 @@ mq_dequeue(struct mbuf_queue *mq)
 int
 mq_enlist(struct mbuf_queue *mq, struct mbuf_list *ml)
 {
-	struct mbuf *m;
 	int dropped = 0;
 
 	mtx_enter(&mq->mq_mtx);
@@ -1472,10 +1464,8 @@ mq_enlist(struct mbuf_queue *mq, struct 
 	}
 	mtx_leave(&mq->mq_mtx);
 
-	if (dropped) {
-		while ((m = ml_dequeue(ml)) != NULL)
-			m_freem(m);
-	}
+	if (dropped)
+		ml_purge(ml);
 
 	return (dropped);
 }