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/write.c b/fs/nfs/write.c
index ac1dc33..c1d5482 100644
--- a/fs/nfs/write.c
+++ b/fs/nfs/write.c
@@ -954,10 +954,8 @@
 
 	nfs_inc_stats(inode, NFSIOS_VFSUPDATEPAGE);
 
-	dprintk("NFS:       nfs_updatepage(%s/%s %d@%lld)\n",
-		file->f_path.dentry->d_parent->d_name.name,
-		file->f_path.dentry->d_name.name, count,
-		(long long)(page_file_offset(page) + offset));
+	dprintk("NFS:       nfs_updatepage(%pD2 %d@%lld)\n",
+		file, count, (long long)(page_file_offset(page) + offset));
 
 	if (nfs_can_extend_write(file, page, inode)) {
 		count = max(count + offset, nfs_page_length(page));