[CRYPTO] ctr: Refactor into ctr and rfc3686

As discussed previously, this patch moves the basic CTR functionality
into a chainable algorithm called ctr.  The IPsec-specific variant of
it is now placed on top with the name rfc3686.

So ctr(aes) gives a chainable cipher with IV size 16 while the IPsec
variant will be called rfc3686(ctr(aes)).  This patch also adjusts
gcm accordingly.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
diff --git a/crypto/gcm.c b/crypto/gcm.c
index 0818317..c54d478 100644
--- a/crypto/gcm.c
+++ b/crypto/gcm.c
@@ -160,7 +160,7 @@
 
 static inline void crypto_gcm_set_counter(u8 *counterblock, u32 value)
 {
-	*((u32 *)&counterblock[12]) = cpu_to_be32(value);
+	*((u32 *)&counterblock[12]) = cpu_to_be32(value + 1);
 }
 
 static int crypto_gcm_encrypt_counter(struct crypto_aead *aead, u8 *block,
@@ -400,9 +400,8 @@
 		return inst;
 
 	inst = ERR_PTR(ENAMETOOLONG);
-	if (snprintf(
-		    ctr_name, CRYPTO_MAX_ALG_NAME,
-		    "ctr(%s,0,16,4)", cipher->cra_name) >= CRYPTO_MAX_ALG_NAME)
+	if (snprintf(ctr_name, CRYPTO_MAX_ALG_NAME, "ctr(%s)",
+		     cipher->cra_name) >= CRYPTO_MAX_ALG_NAME)
 		return inst;
 
 	ctr = crypto_alg_mod_lookup(ctr_name, CRYPTO_ALG_TYPE_BLKCIPHER,