eCryptfs: Filename encryption only supports password auth tokens

Returns -ENOTSUPP when attempting to use filename encryption with
something other than a password authentication token, such as a private
token from openssl.  Using filename encryption with a userspace eCryptfs
key module is a future goal.  Until then, this patch handles the
situation a little better than simply using a BUG_ON().

Acked-by: Serge Hallyn <serue@us.ibm.com>
Cc: ecryptfs-devel@lists.launchpad.net
Cc: stable <stable@kernel.org>
Signed-off-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com>
diff --git a/fs/ecryptfs/crypto.c b/fs/ecryptfs/crypto.c
index f92370a..bae20ad 100644
--- a/fs/ecryptfs/crypto.c
+++ b/fs/ecryptfs/crypto.c
@@ -1703,7 +1703,7 @@
 	} else {
 		printk(KERN_ERR "%s: No support for requested filename "
 		       "encryption method in this release\n", __func__);
-		rc = -ENOTSUPP;
+		rc = -EOPNOTSUPP;
 		goto out;
 	}
 out:
@@ -2168,7 +2168,7 @@
 			(*encoded_name)[(*encoded_name_size)] = '\0';
 			(*encoded_name_size)++;
 		} else {
-			rc = -ENOTSUPP;
+			rc = -EOPNOTSUPP;
 		}
 		if (rc) {
 			printk(KERN_ERR "%s: Error attempting to encode "