Name
netdev_upper_dev_link — 
     Add a link to the upper device
 
Arguments
- dev
- 
     device
     
- upper_dev
- 
     new upper device
     
Description
   Adds a link to device which is upper to this one. The caller must hold
   the RTNL lock. On a failure a negative errno code is returned.
   On success the reference counts are adjusted and the function
   returns zero.