msm: vidc: White space clean up

Restructure some NULL checks to save a level of indentation. This makes
the code slightly more readable and results in less "right aligned" code.

Change-Id: I294069b05d7788f8f801a35f38b35f24cab093a5
Signed-off-by: Deva Ramasubramanian <dramasub@codeaurora.org>