media: iris: Remove redundant buffer count check in stream off

Currently, the stream off process checks the count of buffers in
v4l2_m2m_queues using v4l2_m2m_for_each_src_buf_safe and
v4l2_m2m_for_each_dst_buf_safe APIs. If the count is non-zero, it
returns an error. This check is redundant as the V4L2 framework already
handles buffer management internally.

Remove the unnecessary buffer count check in stream off, simplifying the
process and relying on V4L2's internal mechanisms for buffer management.

Acked-by: Vikash Garodia <quic_vgarodia@quicinc.com>
Tested-by: Neil Armstrong <neil.armstrong@linaro.org> # on SM8550-QRD
Tested-by: Neil Armstrong <neil.armstrong@linaro.org> # on SM8550-HDK
Tested-by: Neil Armstrong <neil.armstrong@linaro.org> # on SM8650-QRD
Tested-by: Neil Armstrong <neil.armstrong@linaro.org> # on SM8650-HDK
Signed-off-by: Dikshita Agarwal <quic_dikshita@quicinc.com>
Tested-by: Vikash Garodia <quic_vgarodia@quicinc.com> # on sa8775p-ride
Signed-off-by: Bryan O'Donoghue <bod@kernel.org>
Signed-off-by: Hans Verkuil <hverkuil@xs4all.nl>