USB: In init_endpoint_class, use PTR_ERR to obtain an errno value, not IS_ERR

init_endpoint_class calls class_create, and checks the result for an error
with IS_ERR; however, if true, it then returns the result of IS_ERR (a
boolean) rather than PTR_ERR (the actual errno).

Signed-off-by: Josh Triplett <[e-mail]>
Signed-off-by: Greg Kroah-Hartman <[e-mail]>

drivers/usb/core/endpoint.c

···
 	kref_init(&ep_class->kref);
 	ep_class->class = class_create(THIS_MODULE, "usb_endpoint");
 	if (IS_ERR(ep_class->class)) {
-		result = IS_ERR(ep_class->class);
+		result = PTR_ERR(ep_class->class);
 		goto class_create_error;
 	}