ovn-controller: Pass 'chassis_id' explicitly to functions that need it.

ovn-controller: Pass 'chassis_id' explicitly to functions that need it.

I found it otherwise difficult to see what code depended on this.  When
later commits make it possible for ovn-controller to handle changes in
chassis ID, this will become important (the code should determine the
current chassis ID before trying to use it).

Signed-off-by: Ben Pfaff <blp@nicira.com>
Acked-by: Justin Pettit <jpettit@nicira.com>