[NET]: Remove in-code externs for some functions from net/core/dev.c

Inconsistent prototype and real type for functions may have worse
consequences, than those for variables, so move them into a header.

Since they are used privately in net/core, make this file reside in
the same place.

Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/core/net-sysfs.h b/net/core/net-sysfs.h
new file mode 100644
index 0000000..f5f108d
--- /dev/null
+++ b/net/core/net-sysfs.h
@@ -0,0 +1,8 @@
+#ifndef __NET_SYSFS_H__
+#define __NET_SYSFS_H__
+
+int netdev_kobject_init(void);
+int netdev_register_kobject(struct net_device *);
+void netdev_unregister_kobject(struct net_device *);
+
+#endif