spinner: Removed unwanted return from function _button_inc_start_cb().
spinner: Removed unwanted return from function _button_inc_start_cb().

This code is a leftover of 617cf8859f0f1fec5ea60fefef446b4454815554.
Now fixed!

rvandegrift/elementary,FlorentRevest/Elementary,rvandegrift/elementary,FlorentRevest/Elementary,rvandegrift/elementary,FlorentRevest/Elementary,rvandegrift/elementary,tasn/elementary,tasn/elementary,tasn/elementary,tasn/elementary,tasn/elementary,FlorentRevest/Elementary