[CRYPTO]: More bug fixes and cleanups.

- added back USAGI copyright for HMAC (lost earlier during some
refactoring).
- bugfix: make sure tfm pointer is set to NULL during post allocation
failure path in crypto_alloc_tfm()

crypto/api.c

@@ -122,6 +122,7 @@ struct crypto_tfm *crypto_alloc_tfm(u32 id)
 		kfree(tfm->crt_ctx);
 out_free_tfm:
 	kfree(tfm);
+	tfm = NULL;
 out_put:
 	crypto_alg_put(alg);
 out:

crypto/digest.c

@@ -5,6 +5,9 @@
  *
  * Copyright (c) 2002 James Morris <jmorris@intercode.com.au>
  *
+ * The HMAC implementation is derived from USAGI.
+ * Copyright (c) 2002 USAGI/WIDE Project
+ *
  * This program is free software; you can redistribute it and/or modify it
  * under the terms of the GNU General Public License as published by the Free
  * Software Foundation; either version 2 of the License, or (at your option)