drivers/video/exynos/s6e8ax0.c: use devm_* APIs in s6e8ax0.c

devm_* APIs are device managed and make error handling and code cleanup
simpler.

Signed-off-by: Sachin Kamat <sachin.kamat@linaro.org>
Acked-by: Donghwa Lee <dh09.lee@samsung.com>
Cc: Inki Dae <inki.dae@samsung.com>
Cc: Florian Tobias Schandinat <FlorianSchandinat@gmx.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>