removed a FIXME note

The issue is not valid, duplicate modules are handled properly.

`RemovedUnusuedKernelModules` is called before saving the config, if the module is used by another card it is added back again later.

Called from https://github.com/yast/yast-sound/blob/71dbc16fdfcb086e04841bf6c091f69554c02c8d/src/include/sound/write_routines.rb#L373, before https://github.com/yast/yast-sound/blob/71dbc16fdfcb086e04841bf6c091f69554c02c8d/src/include/sound/write_routines.rb#L408
as required in comment https://github.com/yast/yast-sound/blob/71dbc16fdfcb086e04841bf6c091f69554c02c8d/src/include/sound/write_routines.rb#L229