ZVISION: Error out when a script file can't be found or be parsed

This should be an error, as we've effectively reached a non-existing
scene (such as in bug #6780), or we haven't parsed script files of a
scene fully, thus unexpected behavior will likely occur

engines/zvision/scripting/scr_file_handling.cpp

@@ -47,15 +47,13 @@ namespace ZVision {
 void ScriptManager::parseScrFile(const Common::String &fileName, ScriptScope &scope) {
 	Common::File file;
 	if (!_engine->getSearchManager()->openFile(file, fileName)) {
-		warning("Script file not found: %s", fileName.c_str());
-		return;
+		error("Script file not found: %s", fileName.c_str());
 	}
 
 	while (!file.eos()) {
 		Common::String line = file.readLine();
 		if (file.err()) {
-			warning("Error parsing scr file: %s", fileName.c_str());
-			return;
+			error("Error parsing scr file: %s", fileName.c_str());
 		}
 
 		trimCommentsAndWhiteSpace(&line);