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/dir.c b/fs/cifs/dir.c
index 4716c54..789ff1d 100644
--- a/fs/cifs/dir.c
+++ b/fs/cifs/dir.c
@@ -40,7 +40,7 @@
 	/* BB check if there is a way to get the kernel to do this or if we
 	   really need this */
 	do {
-		direntry->d_time = jiffies;
+		cifs_set_time(direntry, jiffies);
 		direntry = direntry->d_parent;
 	} while (!IS_ROOT(direntry));
 }
@@ -802,7 +802,7 @@
 
 	} else if (rc == -ENOENT) {
 		rc = 0;
-		direntry->d_time = jiffies;
+		cifs_set_time(direntry, jiffies);
 		d_add(direntry, NULL);
 	/*	if it was once a directory (but how can we tell?) we could do
 		shrink_dcache_parent(direntry); */
@@ -862,7 +862,7 @@
 	if (flags & (LOOKUP_CREATE | LOOKUP_RENAME_TARGET))
 		return 0;
 
-	if (time_after(jiffies, direntry->d_time + HZ) || !lookupCacheEnabled)
+	if (time_after(jiffies, cifs_get_time(direntry) + HZ) || !lookupCacheEnabled)
 		return 0;
 
 	return 1;