Alsa: fix throwing empty exception Calling throw without active exception leads to crash because according to throw definition: "This form is only allowed when an exception is presently being handled (it calls std::terminate if used otherwise)". The fix is to return Alsa::Exception instead. Signed-off-by: Oleksandr Grytsov <[email protected]> Reviewed-by: Oleksandr Andrushchenko <[email protected]>