ipmi: make ipmi_usr_hndl const

It's only function pointers.

Signed-off-by: Corey Minyard <cminyard@mvista.com>
diff --git a/include/linux/ipmi.h b/include/linux/ipmi.h
index 78c5d5a..f1045b2 100644
--- a/include/linux/ipmi.h
+++ b/include/linux/ipmi.h
@@ -100,7 +100,7 @@ struct ipmi_user_hndl {
 
 /* Create a new user of the IPMI layer on the given interface number. */
 int ipmi_create_user(unsigned int          if_num,
-		     struct ipmi_user_hndl *handler,
+		     const struct ipmi_user_hndl *handler,
 		     void                  *handler_data,
 		     ipmi_user_t           *user);