Fix function documentation

CLA: trivial
Reviewed-by: NAndy Polyakov <appro@openssl.org>
Reviewed-by: NRichard Levitte <levitte@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/2972)

include/openssl/ec.h

@@ -573,11 +573,9 @@ int EC_POINT_oct2point(const EC_GROUP *group, EC_POINT *p,
  *  \param  point  EC_POINT object
  *  \param  form   point conversion form
  *  \param  pbuf   returns pointer to allocated buffer
- *  \param  len    length of the memory buffer
  *  \param  ctx    BN_CTX object (optional)
  *  \return the length of the encoded octet string or 0 if an error occurred
  */
-
 size_t EC_POINT_point2buf(const EC_GROUP *group, const EC_POINT *point,
                           point_conversion_form_t form,
                           unsigned char **pbuf, BN_CTX *ctx);
@@ -869,7 +867,7 @@ int EC_KEY_generate_key(EC_KEY *key);
 int EC_KEY_check_key(const EC_KEY *key);
 
 /** Indicates if an EC_KEY can be used for signing.
- *  \param  key  the EC_KEY object
+ *  \param  eckey  the EC_KEY object
  *  \return 1 if can can sign and 0 otherwise.
  */
 int EC_KEY_can_sign(const EC_KEY *eckey);
@@ -888,11 +886,9 @@ int EC_KEY_set_public_key_affine_coordinates(EC_KEY *key, BIGNUM *x,
  *  \param  key    key to encode
  *  \param  form   point conversion form
  *  \param  pbuf   returns pointer to allocated buffer
- *  \param  len    length of the memory buffer
  *  \param  ctx    BN_CTX object (optional)
  *  \return the length of the encoded octet string or 0 if an error occurred
  */
-
 size_t EC_KEY_key2buf(const EC_KEY *key, point_conversion_form_t form,
                       unsigned char **pbuf, BN_CTX *ctx);
 
@@ -927,11 +923,10 @@ int EC_KEY_oct2priv(EC_KEY *key, const unsigned char *buf, size_t len);
 size_t EC_KEY_priv2oct(const EC_KEY *key, unsigned char *buf, size_t len);
 
 /** Encodes an EC_KEY private key to an allocated octet string
- *  \param  key    key to encode
+ *  \param  eckey  key to encode
  *  \param  pbuf   returns pointer to allocated buffer
  *  \return the length of the encoded octet string or 0 if an error occurred
  */
-
 size_t EC_KEY_priv2buf(const EC_KEY *eckey, unsigned char **pbuf);
 
 /********************************************************************/