ASoC: msm:Initialize local variable output_meta_data.

The local variable output_meta_data is not initialized if
prtd->meta_data_mode is false. It can lead unexpected behavior

Change-Id: I64f87342b02a3fb7b5c09c376f72ef7e0ca1efd6
CRs-Fixed:548200
Signed-off-by: Mohammad Johny Shaik <mjshai@codeaurora.org>
Signed-off-by: Satish Kamuju <skamuj@codeaurora.org>