combobox: fix recalc and hover's best_location error
combobox: fix recalc and hover's best_location error

Summary:
1) Recalc error occurs if combobox_hover_begin() was called by the app, it can be reproduced by keeping elm_combobox_hover_begin() in the test_combobox.c
2) Content_set in hover always considered "bottom" as it's best_location as it done during the constructor.
@fix
Signed-off-by: divyesh purohit <div.purohit@samsung.com>

Test Plan:
It can be reproduced by keeping elm_combobox_hover_begin() in the test_combobox.c.
Also the changing the position of combobox in the window would give top/bottom as it's best location.

Reviewers: cedric, shilpasingh

Reviewed By: shilpasingh

Subscribers: rajeshps, govi

Differential Revision: https://phab.enlightenment.org/D3544

Signed-off-by: Cedric BAIL <240633aa59d25638de9800ef43a88ad2e208d24d@osg.samsung.com>

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