fscrypt: use crypto_skcipher_driver_name()

Crypto API users shouldn't really be accessing struct skcipher_alg
directly.  <crypto/skcipher.h> already has a function
crypto_skcipher_driver_name(), so use that instead.

No change in behavior.

Link: https://lore.kernel.org/r/20191209203810.225302-1-ebiggers@kernel.orgSigned-off-by: Eric Biggers <ebiggers@google.com>

fs/crypto/keysetup.c

@@ -89,8 +89,7 @@ struct crypto_skcipher *fscrypt_allocate_skcipher(struct fscrypt_mode *mode,
 		 * first time a mode is used.
 		 */
 		pr_info("fscrypt: %s using implementation \"%s\"\n",
-			mode->friendly_name,
-			crypto_skcipher_alg(tfm)->base.cra_driver_name);
+			mode->friendly_name, crypto_skcipher_driver_name(tfm));
 	}
 	crypto_skcipher_set_flags(tfm, CRYPTO_TFM_REQ_FORBID_WEAK_KEYS);
 	err = crypto_skcipher_setkey(tfm, raw_key, mode->keysize);