elm_win: Initilize the variable 'preferred_rot' as a -1 before invoking _elm_win_xwin_update() in _elm_win_finalize_internal().
elm_win: Initilize the variable 'preferred_rot' as a -1 before invoking _elm_win_xwin_update() in _elm_win_finalize_internal().

Summary:
since the variable 'preferred_rot' is checked its validation in _elm_win_xwin_update(),
so, should be initialize it before invoking.

@fix

Reviewers: jypark, woohyun, Hermet

Reviewed By: Hermet

Differential Revision: https://phab.enlightenment.org/D2987

tasn/elementary,rvandegrift/elementary,tasn/elementary,rvandegrift/elementary,rvandegrift/elementary,tasn/elementary,tasn/elementary,rvandegrift/elementary,tasn/elementary