remoteproc: k3: Correctly release some resources allocated in k3_rproc_request_mbox()

If an error occurs after a successful k3_rproc_request_mbox() call,
mbox_free_channel() should be called to avoid a leak.

Such a call is missing in the error handling path of k3_dsp_rproc_probe().
It is also missing both in the error handling path of k3_m4_rproc_probe()
and in the (in-existent) corresponding remove function.

Switch to managed resources to avoid these leaks and simplify the code.
Remove the now unneeded mbox_free_channel().

Signed-off-by: Christophe JAILLET <[e-mail]>
Reviewed-by: Beleswar Padhi <[e-mail]>
Tested-by: Beleswar Padhi <[e-mail]>
Link: https://lore.kernel.org/r/df853ede72[e-mail]
Signed-off-by: Mathieu Poirier <[e-mail]>

drivers/remoteproc/ti_k3_common.c

···
 }
 EXPORT_SYMBOL_GPL(k3_rproc_release);
 
+static void k3_rproc_free_channel(void *data)
+{
+	struct k3_rproc *kproc = data;
+
+	mbox_free_channel(kproc->mbox);
+}
+
 int k3_rproc_request_mbox(struct rproc *rproc)
 {
 	struct k3_rproc *kproc = rproc->priv;
 	struct mbox_client *client = &kproc->client;
 	struct device *dev = kproc->dev;
+	int ret;
 
 	client->dev = dev;
 	client->tx_done = NULL;
···
 	if (IS_ERR(kproc->mbox))
 		return dev_err_probe(dev, PTR_ERR(kproc->mbox),
 				     "mbox_request_channel failed\n");
+
+	ret = devm_add_action_or_reset(dev, k3_rproc_free_channel, kproc);
+	if (ret)
+		return ret;
 
 	return 0;
 }

drivers/remoteproc/ti_k3_dsp_remoteproc.c

···
 		if (ret)
 			dev_err(dev, "failed to detach proc (%pe)\n", ERR_PTR(ret));
 	}
-
-	mbox_free_channel(kproc->mbox);
 }
 
 static const struct k3_rproc_mem_data c66_mems[] = {

drivers/remoteproc/ti_k3_r5_remoteproc.c

···
 				return;
 			}
 		}
-
-		mbox_free_channel(kproc->mbox);
 	}
 }