Drop retrieve_from_waiting_list() to avoid this warning:

  drivers/scsi/ncr53c8xx.c:8000:26: warning: ‘retrieve_from_waiting_list’
  defined but not used [-Wunused-function]

Link: https://lore.kernel.org/r/YTfS/LH5vCN6afDW@ls3530
Fixes: 1c22e327 ("scsi: ncr53c8xx: Remove unused code")
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Tested-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>