extcon: Fix return value in extcon-class.c

Return the value obtained from the function extcon_register_interest
instead of -ENODEV.

Signed-off-by: Sachin Kamat <[e-mail]>
Signed-off-by: Chanwoo Choi <[e-mail]>
Signed-off-by: Myungjoo Ham <[e-mail]>

drivers/extcon/extcon-class.c

···
 
 		obj->cable_index = extcon_find_cable_index(obj->edev, cable_name);
 		if (obj->cable_index < 0)
-			return -ENODEV;
+			return obj->cable_index;
 
 		obj->user_nb = nb;