video: omapdss: Fix potential null pointer dereference

kmalloc can return null. Add a check to avoid potential null
pointer dereference error when the pointer is accessed later.

Signed-off-by: Sachin Kamat <sachin.kamat@linaro.org>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>

diff --cc drivers/video/fbdev/omap2/dss/omapdss-boot-init.c
Simple merge