media: sun4i-csi: Return queued buffers on start_streaming() failure

media: sun4i-csi: Return queued buffers on start_streaming() failure

The vb2 framework hands buffers to the driver via buf_queue() before
calling start_streaming().  If start_streaming() returns an error
without first returning those buffers via vb2_buffer_done(),
vb2_start_streaming() fires WARN_ON(owned_by_drv_count) and the queued
buffers leak.

sun4i_csi_start_streaming() returned -EINVAL when no matching CSI
format could be found, before any setup (scratch buffer allocation,
pipeline start) had been performed.  The remaining error paths already
converge on the err_clear_dma_queue label, which calls
return_all_buffers(..., VB2_BUF_STATE_QUEUED) under csi->qlock.  Jump
to that label directly: the intermediate err_disable_device /
err_disable_pipeline / err_free_scratch_buffer labels are skipped,
which is correct because nothing they would undo has happened yet.

This mirrors the uvcvideo fix in commit 4cf3b6fd54eb ("media: uvcvideo:
Return queued buffers on start_streaming() failure").

Fixes: 577bbf23b758 ("media: sunxi: Add A10 CSI driver")
Cc: stable@vger.kernel.org
Signed-off-by: Valery Borovsky <vebohr@gmail.com>
Signed-off-by: Hans Verkuil <hverkuil+cisco@kernel.org>