apps: common: options: Avoid copying in range based for loop

The copy can trigger `-Wrange-loop-construct` and is not needed,
so use a reference to avoid it.

Signed-off-by: Barnabás Pőcze <barnabas.pocze@ideasonboard.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>

src/apps/common/options.cpp

@@ -887,7 +887,7 @@ OptionsParser::Options OptionsParser::parse(int argc, char **argv)
 
 	shortOptions[ids++] = ':';
 
-	for (const auto [opt, option] : optionsMap_) {
+	for (const auto &[opt, option] : optionsMap_) {
 		if (option->hasShortOption()) {
 			shortOptions[ids++] = opt;
 			if (option->argument != ArgumentNone)