sunrpc: properly type pc_func callbacks

Drop the argp and resp arguments as they can trivially be derived from
the rqstp argument.  With that all functions now have the same prototype,
and we can remove the unsafe casting to svc_procfunc as well as the
svc_procfunc typedef itself.

Signed-off-by: Christoph Hellwig <hch@lst.de>

include/linux/sunrpc/svc.h

@@ -419,9 +419,9 @@ struct svc_version {
 /*
  * RPC procedure info
  */
-typedef __be32	(*svc_procfunc)(struct svc_rqst *, void *argp, void *resp);
 struct svc_procedure {
-	svc_procfunc		pc_func;	/* process the request */
+	/* process the request: */
+	__be32			(*pc_func)(struct svc_rqst *);
 	kxdrproc_t		pc_decode;	/* XDR decode args */
 	kxdrproc_t		pc_encode;	/* XDR encode result */
 	kxdrproc_t		pc_release;	/* XDR free result */