Fix formatting of 'else' clause.

Also, the logic here doesn't look quite right.  If the driver *has* a 'number_of_channels function', you probably want to call it and use the result even if you don't have a 'get_pin' function.  That way, you can still move offset properly even when a driver doesn't have a 'get_pin' function.

Only when 'channel' falls within the range of the current driver would you check for the 'get_pin' function.