[NET]: Add __dev_getfirstbyhwtype

Add __dev_getfirstbyhwtype for callers that don't want a reference but
some data from the device and thus need to take the rtnl anyway.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index ac0c92b..4428f1c 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -582,6 +582,7 @@
 extern unsigned long		netdev_boot_base(const char *prefix, int unit);
 extern struct net_device    *dev_getbyhwaddr(unsigned short type, char *hwaddr);
 extern struct net_device *dev_getfirstbyhwtype(unsigned short type);
+extern struct net_device *__dev_getfirstbyhwtype(unsigned short type);
 extern void		dev_add_pack(struct packet_type *pt);
 extern void		dev_remove_pack(struct packet_type *pt);
 extern void		__dev_remove_pack(struct packet_type *pt);