gengrid: remove memset to optimize items swapping via keys.
gengrid: remove memset to optimize items swapping via keys.

No need to call memset(0) as struct values are getting fill eventually.

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