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>
1 file changed