[CRYPTO] api: Added cra_init/cra_exit

This patch adds the hooks cra_init/cra_exit which are called during a tfm's
construction and destruction respectively.  This will be used by the instances
to allocate child tfm's.

For now this lets us get rid of the coa_init/coa_exit functions which are
used for exactly that purpose (unlike the dia_init function which is called
for each transaction).

In fact the coa_exit path is currently buggy as it may get called twice
when an error is encountered during initialisation.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

crypto/deflate.c

@@ -201,9 +201,9 @@ static struct crypto_alg alg = {
 	.cra_ctxsize		= sizeof(struct deflate_ctx),
 	.cra_module		= THIS_MODULE,
 	.cra_list		= LIST_HEAD_INIT(alg.cra_list),
+	.cra_init		= deflate_init,
+	.cra_exit		= deflate_exit,
 	.cra_u			= { .compress = {
-	.coa_init		= deflate_init,
-	.coa_exit		= deflate_exit,
 	.coa_compress 		= deflate_compress,
 	.coa_decompress  	= deflate_decompress } }
 };