drm/msm: fix possible uninitialized variable access

Fix the logic so that there is no possibility of using uninitialized
variable values.  This fix is required for when the compiler warning
levels are raised.

Change-Id: I0acf7adfcb48956be975a8c793c1a9a765734abc
Signed-off-by: Steve Cohen <cohens@codeaurora.org>