vxlan: allow a user to set TTL value

"ip link add ... type vxlan ... ttl X" allows a user to set the TTL
used by a VXLAN for encapsulation. The provided value was ignored by
vxlan module and the default value of 1 was used when encapsulating
multicast packets.

Signed-off-by: Vincent Bernat <bernat@luffy.cx>
Acked-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/vxlan.c b/drivers/net/vxlan.c
index 607976c..030559d 100644
--- a/drivers/net/vxlan.c
+++ b/drivers/net/vxlan.c
@@ -1107,6 +1107,9 @@
 	if (data[IFLA_VXLAN_TOS])
 		vxlan->tos  = nla_get_u8(data[IFLA_VXLAN_TOS]);
 
+	if (data[IFLA_VXLAN_TTL])
+		vxlan->ttl = nla_get_u8(data[IFLA_VXLAN_TTL]);
+
 	if (!data[IFLA_VXLAN_LEARNING] || nla_get_u8(data[IFLA_VXLAN_LEARNING]))
 		vxlan->learn = true;