region_add: Fix copying wrong rect during smart merge

region_add: Fix copying wrong rect during smart merge

Summary:
When testing partial rendering on TV, found this bug.
Probably this was caused because of wrong copy/paste.
When region1 completely subsumes region2, region2 should be ignored.
But currently region2 is copied to region1 which makes region1 rect completly wrong.
This was causing lot of visual defects because of wrong rects.
This patch will fix those visual defects when partial rendering is enabled.

Test Plan: Tested with the patch on TV after enabling partial rendering.

Reviewers: raster, cedric, Hermet, ManMower

Reviewed By: ManMower

Subscribers: bu5hm4n, ajwillia.ms, ManMower, devilhorns, cedric, #committers, zmike

Tags: #efl

Differential Revision: https://phab.enlightenment.org/D6696