Handling conditions to avoid PROTECTION_FAULT
[Issue] PROTECTION_FAULT was observed when invalid buffers are sent to VCN.
[Root Cause] The buffer sent to VCN was of buf->size = 0 which is not a valid buffer.
[Fix] Check for such buffers in driver and avoid sending those to VCN. This will not lead to any PROTECTION_FAULT
Signed-off-by: Krunal Patel krunalkumarmukeshkumar.patel@amd.com