is_directional_mode: Check for directional modes directly.

Earlier, the condition was negating all non-directional modes to check
if a mode is directional. This was error-prone, e.g. when a new
non-directional mode is added.

By checking for directional modes directly, we avoid such errors.

Change-Id: Ia4a62e278cd73078c53ed5096db646eff77f054e
2 files changed