Prevent error message generated by parsing 'platform:Linux' for mapping
(gnome-games:28676): Manette-CRITICAL **: 00:25:04.100: Invalid mapping destination: platform
If the destination string is 'platform' we should not try to parse it.
(gnome-games:28676): Manette-CRITICAL **: 00:25:04.100: Invalid mapping destination: platform
If the destination string is 'platform' we should not try to parse it.