openssl: make ossl_send return CURLE_OK better

Previously it only returned a CURLcode for errors, which is when it
returns a different size than what was passed in to it.

The http2 code only checked the curlcode and thus failed.

lib/vtls/openssl.c

@@ -2752,6 +2752,7 @@ static ssize_t ossl_send(struct connectdata *conn,
     *curlcode = CURLE_SEND_ERROR;
     return -1;
   }
+  *curlcode = CURLE_OK;
   return (ssize_t)rc; /* number of bytes */
 }