[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>
diff --git a/crypto/compress.c b/crypto/compress.c
index f3e0733..eca182a 100644
--- a/crypto/compress.c
+++ b/crypto/compress.c
@@ -41,21 +41,14 @@
 
 int crypto_init_compress_ops(struct crypto_tfm *tfm)
 {
-	int ret = 0;
 	struct compress_tfm *ops = &tfm->crt_compress;
-	
-	ret = tfm->__crt_alg->cra_compress.coa_init(tfm);
-	if (ret)
-		goto out;
 
 	ops->cot_compress = crypto_compress;
 	ops->cot_decompress = crypto_decompress;
 	
-out:
-	return ret;
+	return 0;
 }
 
 void crypto_exit_compress_ops(struct crypto_tfm *tfm)
 {
-	tfm->__crt_alg->cra_compress.coa_exit(tfm);
 }