media: mtk-vcodec: vdec: fix incorrect pointer dereference

media: mtk-vcodec: vdec: fix incorrect pointer dereference

mtk_q_data::fmt is actually a pointer and must be dereferenced as such.
This went under the radar because mtk_v4l2_debug() evaluates to nothing
unless DEBUG is defined.

[acourbot: split into its own commit]

Signed-off-by: Yunfei Dong <yunfei.dong@mediatek.com>
Signed-off-by: Alexandre Courbot <acourbot@chromium.org>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>