Don't use ternary operator for JSON validator check (see #3466)

Author: lminiero

src/plugins/janus_sip.c

@@ -3990,10 +3990,15 @@ static void *janus_sip_handler(void *data) {
 				goto error;
 			}
 			janus_mutex_unlock(&session->mutex);
-			struct janus_json_parameter *params = progress ? progress_parameters : accept_parameters;
-			JANUS_VALIDATE_JSON_OBJECT(root, params,
-				error_code, error_cause, TRUE,
-				JANUS_SIP_ERROR_MISSING_ELEMENT, JANUS_SIP_ERROR_INVALID_ELEMENT);
+			if(progress) {
+				JANUS_VALIDATE_JSON_OBJECT(root, progress_parameters,
+					error_code, error_cause, TRUE,
+					JANUS_SIP_ERROR_MISSING_ELEMENT, JANUS_SIP_ERROR_INVALID_ELEMENT);
+			} else {
+				JANUS_VALIDATE_JSON_OBJECT(root, accept_parameters,
+					error_code, error_cause, TRUE,
+					JANUS_SIP_ERROR_MISSING_ELEMENT, JANUS_SIP_ERROR_INVALID_ELEMENT);
+			}
 			if(error_code != 0)
 				goto error;
 			json_t *srtp = json_object_get(root, "srtp");