scsi: use pci_zalloc_consistent

Remove the now unnecessary memset too.

Signed-off-by: Joe Perches <joe@perches.com>
Cc: Adam Radford <linuxraid@lsi.com>
Cc: "James E.J. Bottomley" <JBottomley@parallels.com>
Cc: Jayamohan Kallickal <jayamohan.kallickal@emulex.com>
Cc: Dario Ballabio <ballabio_dario@emc.com>
Cc: Michael Neuffer <mike@i-Connect.Net>
Cc: "Stephen M. Cameron" <scameron@beardog.cce.hp.com>
Cc: Neela Syam Kolli <megaraidlinux@lsi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>