LU-11398 ptlrpc: clean up rq_interpret_reply callbacks

Clean up the function prototypes of several rq_interpret_reply
callback functions to match the function pointer type instead
of using typecasting to avoid the risk of bad function pointers.

Clean up related code to match code style.

Signed-off-by: Andreas Dilger <adilger@whamcloud.com>
Change-Id: I2df73304a8884c1cc838b9c9344d3fd9443ebbe5
Reviewed-on: https://review.whamcloud.com/33203
Reviewed-by: Arshad Hussain <arshad.super@gmail.com>
Reviewed-by: Ben Evans <bevans@cray.com>
Tested-by: Jenkins
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>