usb: ehci: using wIndex + 1 for hub port

The roothub's index per controller is from 0, but the hub port index per hub
is from 1, this patch fixes "can't find device at roohub" problem for connecting
test fixture at roohub when do USB-IF Embedded Host High-Speed Electrical Test.

This patch is for v3.12+.

Cc: [e-mail]
Signed-off-by: Peter Chen <[e-mail]>
Acked-by: Alan Stern <[e-mail]>
Signed-off-by: Greg Kroah-Hartman <[e-mail]>

drivers/usb/host/ehci-hub.c

···
 			if (selector == EHSET_TEST_SINGLE_STEP_SET_FEATURE) {
 				spin_unlock_irqrestore(&ehci->lock, flags);
 				retval = ehset_single_step_set_feature(hcd,
-									wIndex);
+								wIndex + 1);
 				spin_lock_irqsave(&ehci->lock, flags);
 				break;
 			}