usb: usbtmc: use consistent timeout error

- use consistent error value ETIMEOUT instead of ETIME
Tested-by: Dave Penkler <dpenkler@gmail.com>
Reviewed-by: Steve Bayless <steve_bayless@keysight.com>
Signed-off-by: Guido Kiener <guido.kiener@rohde-schwarz.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/class/usbtmc.c

@@ -468,7 +468,7 @@ static int usbtmc488_ioctl_read_stb(struct usbtmc_file_data *file_data,
 
 		if (rv == 0) {
 			dev_dbg(dev, "wait timed out\n");
-			rv = -ETIME;
+			rv = -ETIMEDOUT;
 			goto exit;
 		}