[NETNS][DST] dst: pass the dst_ops as parameter to the gc functions

The garbage collection function receive the dst_ops structure as
parameter. This is useful for the next incoming patchset because it
will need the dst_ops (there will be several instances) and the
network namespace pointer (contained in the dst_ops).

The protocols which do not take care of the namespaces will not be
impacted by this change (expect for the function signature), they do
just ignore the parameter.

Signed-off-by: Daniel Lezcano <dlezcano@fr.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv4/xfrm4_policy.c b/net/ipv4/xfrm4_policy.c
index 656345f..f04516c 100644
--- a/net/ipv4/xfrm4_policy.c
+++ b/net/ipv4/xfrm4_policy.c
@@ -185,7 +185,7 @@
 	fl->fl4_tos = iph->tos;
 }
 
-static inline int xfrm4_garbage_collect(void)
+static inline int xfrm4_garbage_collect(struct dst_ops *ops)
 {
 	xfrm4_policy_afinfo.garbage_collect();
 	return (atomic_read(&xfrm4_dst_ops.entries) > xfrm4_dst_ops.gc_thresh*2);