scsi: fix integer as NULL pointer warnings

drivers/scsi/aic7xxx/aic7770_osm.c:53:58: warning: Using plain integer as NULL pointer
drivers/scsi/aic7xxx/aic7xxx_osm_pci.c:355:47: warning: Using plain integer as NULL pointer
drivers/scsi/aic7xxx/aic7xxx_osm_pci.c:372:55: warning: Using plain integer as NULL pointer
drivers/scsi/aha152x.c:997:28: warning: Using plain integer as NULL pointer
drivers/scsi/aha152x.c:1003:28: warning: Using plain integer as NULL pointer
drivers/scsi/aha152x.c:1165:46: warning: Using plain integer as NULL pointer
drivers/scsi/fdomain.c:1446:40: warning: Using plain integer as NULL pointer
drivers/scsi/sym53c8xx_2/sym_hipd.c:1650:51: warning: Using plain integer as NULL pointer
drivers/scsi/sym53c8xx_2/sym_hipd.c:3171:42: warning: Using plain integer as NULL pointer
drivers/scsi/sym53c8xx_2/sym_hipd.c:5732:52: warning: Using plain integer as NULL pointer
drivers/scsi/ncr53c8xx.c:8189:31: warning: Using plain integer as NULL pointer
drivers/scsi/ncr53c8xx.c:8225:34: warning: Using plain integer as NULL pointer
drivers/scsi/dpt_i2o.c:156:32: warning: Using plain integer as NULL pointer
drivers/scsi/ultrastor.c:954:42: warning: Using plain integer as NULL pointer
drivers/scsi/ultrastor.c:1104:18: warning: Using plain integer as NULL pointer

Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>