genetlink: only pass array to genl_register_family_with_ops()

As suggested by David Miller, make genl_register_family_with_ops()
a macro and pass only the array, evaluating ARRAY_SIZE() in the
macro, this is a little safer.

The openvswitch has some indirection, assing ops/n_ops directly in
that code. This might ultimately just assign the pointers in the
family initializations, saving the struct genl_family_and_ops and
code (once mcast groups are handled differently.)

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/openvswitch/datapath.c b/net/openvswitch/datapath.c
index 91e1c92..8ec8b73 100644
--- a/net/openvswitch/datapath.c
+++ b/net/openvswitch/datapath.c
@@ -1817,8 +1817,9 @@
 	for (i = 0; i < ARRAY_SIZE(dp_genl_families); i++) {
 		const struct genl_family_and_ops *f = &dp_genl_families[i];
 
-		err = genl_register_family_with_ops(f->family, f->ops,
-						    f->n_ops);
+		f->family->ops = f->ops;
+		f->family->n_ops = f->n_ops;
+		err = genl_register_family(f->family);
 		if (err)
 			goto error;
 		n_registered++;