Remove pointless free, and use preferred way of calling d2i_* functions

Reviewed-by: NEmilia Käsper <emilia@openssl.org>

crypto/ec/ec_asn1.c

@@ -1017,14 +1017,8 @@ EC_KEY *d2i_ECPrivateKey(EC_KEY **a, const unsigned char **in, long len)
     EC_KEY *ret = NULL;
     EC_PRIVATEKEY *priv_key = NULL;
 
-    if ((priv_key = EC_PRIVATEKEY_new()) == NULL) {
-        ECerr(EC_F_D2I_ECPRIVATEKEY, ERR_R_MALLOC_FAILURE);
-        return NULL;
-    }
-
-    if ((priv_key = d2i_EC_PRIVATEKEY(&priv_key, in, len)) == NULL) {
+    if ((priv_key = d2i_EC_PRIVATEKEY(NULL, in, len)) == NULL) {
         ECerr(EC_F_D2I_ECPRIVATEKEY, ERR_R_EC_LIB);
-        EC_PRIVATEKEY_free(priv_key);
         return NULL;
     }