libmix: update actual buffer count for AVC

BZ: 184168

If there is a B frame to be output, which should be
excluded in the caculating of buffer count. Otherwize,
the buffer count is not enough then ANR happens.

Change-Id: Ie3d76d5c7f1cbcb73054b68881e07939847fd9f3
Signed-off-by: Tianmi Chen <tianmi.chen@intel.com>
1 file changed