crypto: aead - Add crypto_aead_set_reqsize helper

This patch adds the helper crypto_aead_set_reqsize so that people
don't have to directly access the aead internals to set the reqsize.

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

include/crypto/internal/aead.h

@@ -78,5 +78,11 @@ static inline void aead_givcrypt_complete(struct aead_givcrypt_request *req,
 	aead_request_complete(&req->areq, err);
 }
 
+static inline void crypto_aead_set_reqsize(struct crypto_aead *aead,
+					   unsigned int reqsize)
+{
+	crypto_aead_crt(aead)->reqsize = reqsize;
+}
+
 #endif	/* _CRYPTO_INTERNAL_AEAD_H */