mm-video-v4l2: Don't allocate C2D buffers twice

The call to allocate intermediate C2D buffers is happening
twice. Avoid this as the allocation is failing 2nd time and
causing further problems.

CRs-Fixed: 2280521
Change-Id: I98e2e7b6b6301e39c3c59ad8d3a4a041ac6b2628
1 file changed