msm: vidc: Add change in error check for FW buffer requirements

FW buffer requirements for some buffers can be zero.
Driver treat them as an error and returing bad buffer
requirement which are actually valid.Add a fix to
process the FW buffer requirement correctly.

Change-Id: I7116fe5a03be77d10b1ecab737f0f3504377f80f
Signed-off-by: Praneeth Paladugu <ppaladug@codeaurora.org>