[SCSI] pm80xx: remove unneeded NULL check

Coccinelle complains about the inconsistent NULL checking on "t".  It
turns out the check isn't needed because we verified that "t" is
non-NULL at the start of the function.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Acked-by: Anand Kumar Santhanam <AnandKumar.Santhanam@pmcs.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>