Name
idr_replace — 
     replace pointer for given id
 
Synopsis
| void * idr_replace ( | struct idr * idp, | 
|  | void * ptr, | 
|  | int id ); | 
 
Arguments
- idp
- 
     idr handle
     
- ptr
- 
     pointer you want associated with the id
     
- id
- 
     lookup key
     
Description
   Replace the pointer registered with an id and return the old value.
   A -ENOENT return indicates that id was not found.
   A -EINVAL return indicates that id was not within valid constraints.
   
   The caller must serialize with writers.