wimax: usb-fw: mark expected switch fall-through

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

Notice that in this particular case, I placed the "fall through"
annotation at the bottom of the case, which is what GCC is expecting
to find.

Addresses-Coverity-ID: 1369529 ("Missing break in switch")
Signed-off-by: Gustavo A. R. Silva <[email protected]>
Signed-off-by: David S. Miller <[email protected]>

drivers/net/wimax/i2400m/usb-fw.c

@@ -130,12 +130,12 @@ ssize_t i2400mu_tx_bulk_out(struct i2400mu *i2400mu, void *buf, size_t buf_size)
 			dev_err(dev, "BM-CMD: too many stalls in "
 				"URB; resetting device\n");
 			usb_queue_reset_device(i2400mu->usb_iface);
-			/* fallthrough */
 		} else {
 			usb_clear_halt(i2400mu->usb_dev, pipe);
 			msleep(10);	/* give the device some time */
 			goto retry;
 		}
+		/* fall through */
 	case -EINVAL:			/* while removing driver */
 	case -ENODEV:			/* dev disconnect ... */
 	case -ENOENT:			/* just ignore it */