usb: host: dwc3-sti-glue: Fix ofnode_valid() parameter

node varaible is used as iterator into ofnode_for_each_subnode()
loop, when exiting of it, node is no more a valid ofnode.
Use dwc3_node instead as parameter of ofnode_valid()

Fixes: ac28e59a574d ("usb: Migrate to support live DT for some driver")
Signed-off-by: Patrice Chotard <patrice.chotard@st.com>
Cc: Kever Yang <kever.yang@rock-chips.com>
diff --git a/drivers/usb/host/dwc3-sti-glue.c b/drivers/usb/host/dwc3-sti-glue.c
index a72ab20..3e6c142 100644
--- a/drivers/usb/host/dwc3-sti-glue.c
+++ b/drivers/usb/host/dwc3-sti-glue.c
@@ -159,7 +159,7 @@
 			dwc3_node = node;
 	}
 
-	if (!ofnode_valid(node)) {
+	if (!ofnode_valid(dwc3_node)) {
 		pr_err("Can't find dwc3 subnode for %s\n", dev->name);
 		return -ENODEV;
 	}