[SCSI] aic7xxx_old: remove redundant GFP_ATOMIC from kmalloc

drivers/scsi/aic7xxx_old.c:aic7xxx_slave_alloc() unnecessarily passes
GFP_ATOMIC (along with GFP_KERNEL) to kmalloc() from a context that is not
atomic. Remove the pointless GFP_ATOMIC.

Signed-off-by: Satyam Sharma <ssatyam@cse.iitk.ac.in>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Doug Ledford <dledford@redhat.com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>