SUNRPC: Ensure rpc_task->tk_pid is available for tracepoints

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
diff --git a/net/sunrpc/sched.c b/net/sunrpc/sched.c
index 93a7a4e..ff3cc4b 100644
--- a/net/sunrpc/sched.c
+++ b/net/sunrpc/sched.c
@@ -258,7 +258,7 @@
 	return 0;
 }
 
-#ifdef RPC_DEBUG
+#if defined(RPC_DEBUG) || defined(RPC_TRACEPOINTS)
 static void rpc_task_set_debuginfo(struct rpc_task *task)
 {
 	static atomic_t rpc_pid;