apps: Define local functions in anonymous namespace

Multiple local functions are defined in the global namespace without the
static keyword. This compiles fine for now, but will cause a missing
declaration warning when we enable them. To prepare for that, move the
function declaration to an anonymous namespace.

While at it, for consistency, include an existing static function in the
namespace and drop the static keyword.

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

src/apps/cam/main.cpp

@@ -344,12 +344,16 @@ std::string CamApp::cameraName(const Camera *camera)
 	return name;
 }
 
+namespace {
+
 void signalHandler([[maybe_unused]] int signal)
 {
 	std::cout << "Exiting" << std::endl;
 	CamApp::instance()->quit();
 }
 
+} /* namespace */
+
 int main(int argc, char **argv)
 {
 	CamApp app;