dm crypt: Initialize crypto wait structures

Use the DECLARE_CRYPTO_WAIT() macro to properly initialize the crypto
wait structures declared on stack before their use with
crypto_wait_req().

Fixes: 39d13a1 ("dm crypt: reuse eboiv skcipher for IV generation")
Fixes: bbb1658 ("dm crypt: Implement Elephant diffuser for Bitlocker compatibility")
Cc: stable@vger.kernel.org
Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>

drivers/md/dm-crypt.c

@@ -739,7 +739,7 @@ static int crypt_iv_eboiv_gen(struct crypt_config *cc, u8 *iv,
 	u8 buf[MAX_CIPHER_BLOCKSIZE] __aligned(__alignof__(__le64));
 	struct skcipher_request *req;
 	struct scatterlist src, dst;
-	struct crypto_wait wait;
+	DECLARE_CRYPTO_WAIT(wait);
 	int err;
 
 	req = skcipher_request_alloc(any_tfm(cc), GFP_NOIO);
@@ -936,7 +936,7 @@ static int crypt_iv_elephant(struct crypt_config *cc, struct dm_crypt_request *d
 	u8 *es, *ks, *data, *data2, *data_offset;
 	struct skcipher_request *req;
 	struct scatterlist *sg, *sg2, src, dst;
-	struct crypto_wait wait;
+	DECLARE_CRYPTO_WAIT(wait);
 	int i, r;
 
 	req = skcipher_request_alloc(elephant->tfm, GFP_NOIO);