fbdev: msm: Fix unintialisation of variables

The uninitialised variables in MDP driver can be accessed
with incorrect values. This change fixes the errors reported
in static analysis of MDP driver code.

Change-Id: I69193a1243d17dfb88e51717179e9f2ed2c4b5df
Signed-off-by: Raghavendra Ambadas <rambad@codeaurora.org>