media: mediatek: encoder: Fix uninitialized scalar variable issue

media: mediatek: encoder: Fix uninitialized scalar variable issue

UNINIT checker finds some instances of variables that are used
without being initialized, for example using the uninitialized
value enc_result.is_key_frm can result in unpredictable behavior,
so initialize these variables after declaring.

Fixes: 4e855a6efa54 ("[media] vcodec: mediatek: Add Mediatek V4L2 Video Encoder Driver")
Cc: stable@vger.kernel.org
Signed-off-by: Irui Wang <irui.wang@mediatek.com>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Signed-off-by: Nicolas Dufresne <nicolas.dufresne@collabora.com>
Signed-off-by: Hans Verkuil <hverkuil+cisco@kernel.org>