media: iris: Fix memory leak by freeing untracked persist buffer

commit 02a24f13 upstream.

One internal buffer which is allocated only once per session was not
being freed during session close because it was not being tracked as
part of internal buffer list which resulted in a memory leak.

Add the necessary logic to explicitly free the untracked internal buffer
during session close to ensure all allocated memory is released
properly.

Fixes: 73702f45 ("media: iris: allocate, initialize and queue internal buffers")
Cc: stable@vger.kernel.org
Reviewed-by: Vikash Garodia <quic_vgarodia@quicinc.com>
Tested-by: Vikash Garodia <quic_vgarodia@quicinc.com> # X1E80100
Tested-by: Neil Armstrong <neil.armstrong@linaro.org> # on SM8550-HDK
Tested-by: Neil Armstrong <neil.armstrong@linaro.org> # on SM8650-HDK
Signed-off-by: Dikshita Agarwal <quic_dikshita@quicinc.com>
Tested-by: Bryan O'Donoghue <bryan.odonoghue@linaro.org> # x1e80100-crd
Signed-off-by: Bryan O'Donoghue <bod@kernel.org>
Signed-off-by: Hans Verkuil <hverkuil+cisco@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>