CHROMIUM: drm/exynos: fb: Cleanup exynos_drm_fb_init

CHROMIUM: drm/exynos: fb: Cleanup exynos_drm_fb_init

Return a pointer to an exynos_drm_fb instead of its drm_framebuffer field.
This seems more logical.

Signed-off-by: Daniel Kurtz <djkurtz@chromium.org>
BUG=chromium-os:37097
TEST=compile test

Change-Id: I990e186ca09769b725de3d10e5b20ae34470a322
Reviewed-on: https://gerrit.chromium.org/gerrit/39478
Reviewed-by: Stéphane Marchesin <marcheu@chromium.org>
Commit-Ready: Daniel Kurtz <djkurtz@chromium.org>
Reviewed-by: Daniel Kurtz <djkurtz@chromium.org>
Tested-by: Daniel Kurtz <djkurtz@chromium.org>