win: fix segfaults (wrong checking)
win: fix segfaults (wrong checking)

Summary:
There were wrong checkings in elm_win_size_base_get and
elm_win_size_step_get
@fix

Reviewers: seoz, Hermet

Differential Revision: https://phab.enlightenment.org/D1533

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