media: imx-jpeg: fix a bug of accessing array out of bounds

When error occurs in parsing jpeg, the slot isn't acquired yet, it may
be the default value MXC_MAX_SLOTS.
If the driver access the slot using the incorrect slot number, it will
access array out of bounds.
The result is the driver will change num_domains, which follows
slot_data in struct mxc_jpeg_dev.
Then the driver won't detach the pm domain at rmmod, which will lead to
kernel panic when trying to insmod again.

Signed-off-by: Ming Qian <[email protected]>
Reviewed-by: Mirela Rabulea <[email protected]>
Signed-off-by: Hans Verkuil <[email protected]>

drivers/media/platform/imx-jpeg/mxc-jpeg.c

@@ -954,7 +954,6 @@ static void mxc_jpeg_device_run(void *priv)
 		jpeg_src_buf->jpeg_parse_error = true;
 	}
 	if (jpeg_src_buf->jpeg_parse_error) {
-		jpeg->slot_data[ctx->slot].used = false;
 		v4l2_m2m_src_buf_remove(ctx->fh.m2m_ctx);
 		v4l2_m2m_dst_buf_remove(ctx->fh.m2m_ctx);
 		v4l2_m2m_buf_done(src_buf, VB2_BUF_STATE_ERROR);