crypto: ecdh - return unsigned value for crypto_ecdh_key_len()

ECDH_KPP_SECRET_MIN_SIZE and params->key_size are both returning
unsigned values.
Signed-off-by: Tudor Ambarus <tudor.ambarus@microchip.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

crypto/ecdh_helper.c

@@ -28,7 +28,7 @@ static inline const u8 *ecdh_unpack_data(void *dst, const void *src, size_t sz)
 	return src + sz;
 }
 
-int crypto_ecdh_key_len(const struct ecdh *params)
+unsigned int crypto_ecdh_key_len(const struct ecdh *params)
 {
 	return ECDH_KPP_SECRET_MIN_SIZE + params->key_size;
 }

include/crypto/ecdh.h

@@ -54,7 +54,7 @@ struct ecdh {
  *
  * Return: size of the key in bytes
  */
-int crypto_ecdh_key_len(const struct ecdh *params);
+unsigned int crypto_ecdh_key_len(const struct ecdh *params);
 
 /**
  * crypto_ecdh_encode_key() - encode the private key