nfs: use %p[dD] instead of open-coded (and often racy) equivalents

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/fs/nfs/namespace.c b/fs/nfs/namespace.c
index 348b535..b5a0afc 100644
--- a/fs/nfs/namespace.c
+++ b/fs/nfs/namespace.c
@@ -253,9 +253,8 @@
 
 	dprintk("--> nfs_do_submount()\n");
 
-	dprintk("%s: submounting on %s/%s\n", __func__,
-			dentry->d_parent->d_name.name,
-			dentry->d_name.name);
+	dprintk("%s: submounting on %pd2\n", __func__,
+			dentry);
 	if (page == NULL)
 		goto out;
 	devname = nfs_devname(dentry, page, PAGE_SIZE);