net: l3mdev: Remove const from flowi6 arg to get_rt6_dst

Allow drivers to pass flow arg to functions where the arg is not const
and allow the driver to make updates as needed (eg., setting oif).

Signed-off-by: David Ahern <dsa@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/vrf.c b/drivers/net/vrf.c
index b4d7469..d2ce76c 100644
--- a/drivers/net/vrf.c
+++ b/drivers/net/vrf.c
@@ -861,7 +861,7 @@
 
 #if IS_ENABLED(CONFIG_IPV6)
 static struct dst_entry *vrf_get_rt6_dst(const struct net_device *dev,
-					 const struct flowi6 *fl6)
+					 struct flowi6 *fl6)
 {
 	struct dst_entry *dst = NULL;