Squashed commit of the following:

    configs/z80sim and xtrs:  Serial driver lower halfs ioctl methods should return a negated errno value, not set the errno variable.

    drivers/wireless:  CC1101 driver not permitted to set errno.

    drivers/sensors:  LIS331DL driver not permitted to set errno.

    drivers/lcd: ILI9341 initialize method not permitted to set errno,

    drivers/serial: 16550 UART driver IOCTL method must not set errno; it must return a negated errno value.