usb: hso: remove bogus check for EINPROGRESS

This check an inherent race. It opens a race where
an error code has already been set or cleared yet
the URB has not been given back. We cannot do
such an optimization and must unlink unconditionally.

Signed-off-by: Oliver Neukum <oneukum@suse.com>
Signed-off-by: David S. Miller <davem@davemloft.net>