msm: camera2: cpp: Release vb2 buffer in cpp driver on error

When duplicate output is enabled, there is potential issue if
error is encountered in second output buffer. Under error condition
related to second output buffer is hit, the first output buffer is
not released properly.

Change-Id: I56f375a5783c54c450f5673818d15b393f469ef1
Signed-off-by: Rajakumar Govindaram <rajakuma@codeaurora.org>