efl: remove some warnings.

efl: remove some warnings.

Summary:
Mainly from the examples but also from libunibreak and tests/eet.

I'm not sure if it's really worth to remove warnings from the examples
-- because it adds pedantic-ness to something supposed to be didatic,
but I leave for you guys to judge.

Reviewers: tasn, cedric

CC: felipealmeida, raster, smohanty, cedric
Differential Revision: https://phab.enlightenment.org/D896

Signed-off-by: Cedric Bail <cedric.bail@free.fr>