staging: octeon-usb: cvmx-usb: utilize Linux error codes

Use generic Linux error codes to replace cvmx_usb_status_t.

The conversion table:

	Before				After
	cvmx_usb_status_t		int
	CVMX_USB_SUCCESS		0
	CVMX_USB_INVALID_PARAM		-EINVAL
	CVMX_USB_NO_MEMORY		-ENOMEM
	CVMX_USB_BUSY			-EBUSY
	CVMX_USB_TIMEOUT		-ETIMEDOUT
	CVMX_USB_INCORRECT_MODE		Deleted (was never used)

Signed-off-by: Aaro Koskinen <aaro.koskinen@iki.fi>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>