Update github.com/vishvananda/netlink to v1.2.0-beta

Latest version fixes a segfault when used on some ppp setup

Signed-off-by: Dominique Martinet <dominique.martinet@atmark-techno.com>

vendor/github.com/vishvananda/netlink/nl/lwt_linux.go

@@ -0,0 +1,29 @@
+package nl
+
+const (
+	LWT_BPF_PROG_UNSPEC = iota
+	LWT_BPF_PROG_FD
+	LWT_BPF_PROG_NAME
+	__LWT_BPF_PROG_MAX
+)
+
+const (
+	LWT_BPF_PROG_MAX = __LWT_BPF_PROG_MAX - 1
+)
+
+const (
+	LWT_BPF_UNSPEC = iota
+	LWT_BPF_IN
+	LWT_BPF_OUT
+	LWT_BPF_XMIT
+	LWT_BPF_XMIT_HEADROOM
+	__LWT_BPF_MAX
+)
+
+const (
+	LWT_BPF_MAX = __LWT_BPF_MAX - 1
+)
+
+const (
+	LWT_BPF_MAX_HEADROOM = 256
+)