msm: vidc: Add error check before calling release buffers to FW

Release buffers can be called in any FW state. If release
buffers called in non-release reources state, the FW might
use them whereas the driver will unmap them causing IOMMU page fault.

Change-Id: I21e7ac3e696594c0a802bd6066ef7a9a3ab9f12b
Signed-off-by: Praneeth Paladugu <ppaladug@codeaurora.org>