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/nfs4file.c b/fs/nfs/nfs4file.c
index 77efaf1..9c8f09a 100644
--- a/fs/nfs/nfs4file.c
+++ b/fs/nfs/nfs4file.c
@@ -31,9 +31,7 @@
 	 * -EOPENSTALE.  The VFS will retry the lookup/create/open.
 	 */
 
-	dprintk("NFS: open file(%s/%s)\n",
-		dentry->d_parent->d_name.name,
-		dentry->d_name.name);
+	dprintk("NFS: open file(%pd2)\n", dentry);
 
 	if ((openflags & O_ACCMODE) == 3)
 		openflags--;