cifs: don't use ->d_time

Use d_fsdata instead, which is the same size.  Introduce helpers to hide
the typecasts.

Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Cc: Steve French <sfrench@samba.org>
diff --git a/fs/cifs/inode.c b/fs/cifs/inode.c
index b87efd0..0b4a355 100644
--- a/fs/cifs/inode.c
+++ b/fs/cifs/inode.c
@@ -1951,7 +1951,7 @@
 
 	cifs_dbg(FYI, "Update attributes: %s inode 0x%p count %d dentry: 0x%p d_time %ld jiffies %ld\n",
 		 full_path, inode, inode->i_count.counter,
-		 dentry, dentry->d_time, jiffies);
+		 dentry, cifs_get_time(dentry), jiffies);
 
 	if (cifs_sb_master_tcon(CIFS_SB(sb))->unix_ext)
 		rc = cifs_get_inode_info_unix(&inode, full_path, sb, xid);