spelling: s/trough/through/

Additionally, one comment was reformulated by Joe Perches <joe@perches.com>.

Signed-off-by: Adrian Bunk <bunk@stusta.de>
diff --git a/drivers/usb/serial/usb-serial.c b/drivers/usb/serial/usb-serial.c
index 8bc8337..4dd6865 100644
--- a/drivers/usb/serial/usb-serial.c
+++ b/drivers/usb/serial/usb-serial.c
@@ -584,7 +584,7 @@
 	const struct usb_device_id *id;
 	struct usb_serial_driver *t;
 
-	/* List trough know devices and see if the usb id matches */
+	/* Check if the usb id matches a known device */
 	list_for_each(p, &usb_serial_driver_list) {
 		t = list_entry(p, struct usb_serial_driver, driver_list);
 		id = usb_match_id(iface, t->id_table);