[media] coda: fix error return value if v4l2_m2m_ctx_init fails

Use ret from the outer scope, instead of redefining it in the
conditional clause. That way the error value reaches the end of
the function as intended.
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

drivers/media/platform/coda.c

@@ -1484,7 +1484,7 @@ static int coda_open(struct file *file)
 	ctx->m2m_ctx = v4l2_m2m_ctx_init(dev->m2m_dev, ctx,
 					 &coda_queue_init);
 	if (IS_ERR(ctx->m2m_ctx)) {
-		int ret = PTR_ERR(ctx->m2m_ctx);
+		ret = PTR_ERR(ctx->m2m_ctx);
 
 		v4l2_err(&dev->v4l2_dev, "%s return error (%d)\n",
 			 __func__, ret);