scsi: aic7xxx: Remove unused variable 'ahd'

Hasn't been used since 2005.

Fixes the following W=1 kernel build warning(s):

 drivers/scsi/aic7xxx/aic79xx_osm.c: In function ‘ahd_linux_slave_configure’:
 drivers/scsi/aic7xxx/aic79xx_osm.c:703:20: warning: variable ‘ahd’ set but not used [-Wunused-but-set-variable]

Link: https://lore.kernel.org/r/20200713080001.128044-22-lee.jones@linaro.org


Cc: Hannes Reinecke <hare@suse.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>