bus: fsl-mc: fsl-mc-allocator: Improve error reporting

Instead of silently returning an error in the remove callback (which yields
a generic and little informing error message), annotate each error path of
fsl_mc_resource_pool_remove_device() with an error message and return zero
in the remove callback to suppress the error message.

Note that changing the return value has no other effect than suppressing
the error message by the fsl_mc bus driver.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Reviewed-by: Ioana Ciornei <ioana.ciornei@nxp.com>
Tested-by: Ioana Ciornei <ioana.ciornei@nxp.com> # sanity checks
Reviewed-by: Laurentiu Tudor <laurentiu.tudor@nxp.com>
Tested-by: Laurentiu Tudor <laurentiu.tudor@nxp.com>
Signed-off-by: Li Yang <leoyang.li@nxp.com>

Author: Uwe Kleine-König

drivers/bus/fsl-mc/fsl-mc-allocator.c

@@ -104,22 +104,30 @@ static int __must_check fsl_mc_resource_pool_remove_device(struct fsl_mc_device
 	int error = -EINVAL;
 
 	resource = mc_dev->resource;
-	if (!resource || resource->data != mc_dev)
+	if (!resource || resource->data != mc_dev) {
+		dev_err(&mc_bus_dev->dev, "resource mismatch\n");
 		goto out;
+	}
 
 	mc_bus_dev = to_fsl_mc_device(mc_dev->dev.parent);
 	mc_bus = to_fsl_mc_bus(mc_bus_dev);
 	res_pool = resource->parent_pool;
-	if (res_pool != &mc_bus->resource_pools[resource->type])
+	if (res_pool != &mc_bus->resource_pools[resource->type]) {
+		dev_err(&mc_bus_dev->dev, "pool mismatch\n");
 		goto out;
+	}
 
 	mutex_lock(&res_pool->mutex);
 
-	if (res_pool->max_count <= 0)
+	if (res_pool->max_count <= 0) {
+		dev_err(&mc_bus_dev->dev, "max_count underflow\n");
 		goto out_unlock;
+	}
 	if (res_pool->free_count <= 0 ||
-	    res_pool->free_count > res_pool->max_count)
+	    res_pool->free_count > res_pool->max_count) {
+		dev_err(&mc_bus_dev->dev, "free_count mismatch\n");
 		goto out_unlock;
+	}
 
 	/*
 	 * If the device is currently allocated, its resource is not
@@ -613,7 +621,7 @@ static int fsl_mc_allocator_remove(struct fsl_mc_device *mc_dev)
 	if (mc_dev->resource) {
 		error = fsl_mc_resource_pool_remove_device(mc_dev);
 		if (error < 0)
-			return error;
+			return 0;
 	}
 
 	dev_dbg(&mc_dev->dev,