usb: host: ehci-hcd: mark expected switch fall-through

In preparation to enabling -Wimplicit-fallthrough, mark switch cases
where we are expecting to fall through.

Signed-off-by: Gustavo A. R. Silva <garsilva@embeddedor.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/host/ehci-hcd.c

@@ -1012,7 +1012,7 @@ idle_timeout:
 			qh_destroy(ehci, qh);
 			break;
 		}
-		/* else FALL THROUGH */
+		/* fall through */
 	default:
 		/* caller was supposed to have unlinked any requests;
 		 * that's not our job.  just leak this memory.