linux-user: Add support for FD<SETEMSGTRESH|SETMAXERRS|GETMAXERRS> ioctls

linux-user: Add support for FD<SETEMSGTRESH|SETMAXERRS|GETMAXERRS> ioctls

FDSETEMSGTRESH, FDSETMAXERRS, and FDGETMAXERRS ioctls are commands
for controlling error reporting of a floppy drive.

FDSETEMSGTRESH's third agrument is a pointer to the structure:

struct floppy_max_errors {
    unsigned int
      abort,      /* number of errors to be reached before aborting */
      read_track, /* maximal number of errors permitted to read an
                   * entire track at once */
      reset,      /* maximal number of errors before a reset is tried */
      recal,      /* maximal number of errors before a recalibrate is
                   * tried */
      /*
       * Threshold for reporting FDC errors to the console.
       * Setting this to zero may flood your screen when using
       * ultra cheap floppies ;-)
       */
      reporting;
};

defined in Linux kernel header <linux/fd.h>.

Since all fields of the structure are of type 'unsigned int', there is
no need to define "target_floppy_max_errors".

FDSETMAXERRS and FDGETMAXERRS ioctls do not use the third argument.

Reviewed-by: Laurent Vivier <laurent@vivier.eu>
Signed-off-by: Aleksandar Markovic <amarkovic@wavecomp.com>
Message-Id: <1579214991-19602-8-git-send-email-aleksandar.markovic@rt-rk.com>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>