Function has_custom_logo when used in Customizer

You have it around the wrong way has_custom_logo() will return false if there is no logo.
function_exists( 'the_custom_logo' ) however will return true if you are using a version of WordPress that support this function.

So if you seperate your if statement like below it will work.

if( function_exists( 'the_custom_logo' ) ) {
    if(has_custom_logo()) {
        the_custom_logo();
    } else {
        echo "No logo";
    }
}