genetlink: pass family to functions using groups

This doesn't really change anything, but prepares for the
next patch that will change the APIs to pass the group ID
within the family, rather than the global group ID.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/acpi/event.c

@@ -146,7 +146,8 @@ int acpi_bus_generate_netlink_event(const char *device_class,
 		return result;
 	}
 
-	genlmsg_multicast(skb, 0, acpi_event_mcgrp.id, GFP_ATOMIC);
+	genlmsg_multicast(&acpi_event_genl_family,
+			  skb, 0, acpi_event_mcgrp.id, GFP_ATOMIC);
 	return 0;
 }