Update to FreeBSD head 2018-04-01

Git mirror commit 8dfb1ccc26d1cea7e2529303003ff61f9f1784c4.

Update #3472.

freebsd/sbin/route/route.c

@@ -578,6 +578,7 @@ retry:
 			printf("done\n");
 		}
 	}
+	free(buf);
 	return (error);
 }
 
@@ -1498,6 +1499,7 @@ retry2:
 		rtm = (struct rt_msghdr *)(void *)next;
 		print_rtmsg(rtm, rtm->rtm_msglen);
 	}
+	free(buf);
 }
 
 static void
@@ -1578,8 +1580,10 @@ rtmsg(int cmd, int flags, int fib)
 			so[RTAX_IFP].ss_len = sizeof(struct sockaddr_dl);
 			rtm_addrs |= RTA_IFP;
 		}
-	} else
+	} else {
 		cmd = RTM_DELETE;
+		flags |= RTF_PINNED;
+	}
 #define rtm m_rtmsg.m_rtm
 	rtm.rtm_type = cmd;
 	rtm.rtm_flags = flags;