USB: Fix unused label warnings in drivers/usb/host/ehci-hcd.c

This gets rid of an annoying warning in ehci-hcd.c when DEBUG isn't
enabled:

    warning: label 'err_debug' defined but not used

by moving it inside the already-existing #ifdef DEBUG, so that it
matches the goto.  And now my regular build is warning-free again.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drivers/usb/host/ehci-hcd.c

@@ -1111,8 +1111,8 @@ clean0:
 #ifdef DEBUG
 	debugfs_remove(ehci_debug_root);
 	ehci_debug_root = NULL;
-#endif
 err_debug:
+#endif
 	clear_bit(USB_EHCI_LOADED, &usb_hcds_loaded);
 	return retval;
 }