media: c8sectpfe: fix double free in configure_channels()

The configure_channels() function has a double free because
configure_memdma_and_inputblock() calls free_input_block() and then
it's called again in the error handling code.

Link: https://lore.kernel.org/linux-media/20211208073544.GA22020@kili
Fixes: c5f5d0f9 ("[media] c8sectpfe: STiH407/10 Linux DVB demux support")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Patrice Chotard <patrice.chotard@foss.st.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>

drivers/media/platform/sti/c8sectpfe/c8sectpfe-core.c

@@ -925,7 +925,6 @@ static int c8sectpfe_remove(struct platform_device *pdev)
 static int configure_channels(struct c8sectpfei *fei)
 {
 	int index = 0, ret;
-	struct channel_info *tsin;
 	struct device_node *child, *np = fei->dev->of_node;
 
 	/* iterate round each tsin and configure memdma descriptor and IB hw */
@@ -943,10 +942,9 @@ static int configure_channels(struct c8sectpfei *fei)
 	return 0;
 
 err_unmap:
-	for (index = 0; index < fei->tsin_count; index++) {
-		tsin = fei->channel_data[index];
-		free_input_block(fei, tsin);
-	}
+	while (--index >= 0)
+		free_input_block(fei, fei->channel_data[index]);
+
 	return ret;
 }