drivers/video/msm/mdp.c: fix merge derp!

Signed-off-by: Paul Reioux <reioux@gmail.com>
Signed-off-by: flar2 <asegaert@gmail.com>

idea is taken here -
https://github.com/flar2/m7-Sense/commit/aa130d45cdb45e16a4954b6f88b9c2803ce69acd