SUNRPC: Add trace events to the sunrpc subsystem

Add declarations to allow tracing of RPC call creation, running, sleeping,
and destruction.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
diff --git a/include/linux/sunrpc/sched.h b/include/linux/sunrpc/sched.h
index bd337f9..f7b2df5 100644
--- a/include/linux/sunrpc/sched.h
+++ b/include/linux/sunrpc/sched.h
@@ -271,7 +271,7 @@
 }
 
 #ifdef RPC_DEBUG
-static inline const char * rpc_qname(struct rpc_wait_queue *q)
+static inline const char * rpc_qname(const struct rpc_wait_queue *q)
 {
 	return ((q && q->name) ? q->name : "unknown");
 }