Expecting the caller to free the mask requires us to keep it in a single
memory block (which may be an issue lateron), aside from leaving the API
asymetrical. Provide valuator_mask_free() to free the memory and reset the
mask pointer to NULL.
Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>
Reviewed-by: Fernando Carrijo <fcarrijo@freedesktop.org>
Reviewed-by: Chase Douglas <chase.douglas@canonical.com>