nfs: Remove invalid tk_pid from debug message

Before rpc_run_task(), tk_pid is uninitiated as 0 always.

Signed-off-by: Kinglong Mee <kinglongmee@gmail.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
diff --git a/fs/nfs/write.c b/fs/nfs/write.c
index 84ba726..359e9ad 100644
--- a/fs/nfs/write.c
+++ b/fs/nfs/write.c
@@ -1551,7 +1551,7 @@
 	/* Set up the initial task struct.  */
 	nfs_ops->commit_setup(data, &msg);
 
-	dprintk("NFS: %5u initiated commit call\n", data->task.tk_pid);
+	dprintk("NFS: initiated commit call\n");
 
 	nfs4_state_protect(NFS_SERVER(data->inode)->nfs_client,
 		NFS_SP4_MACH_CRED_COMMIT, &task_setup_data.rpc_client, &msg);