[SCSI] be2iscsi: Remove unused OFFSET_IN_PAGE() macro

Signed-off-by: Roland Dreier <roland@purestorage.com>
Reviewed-by: Mike Christie <michaelc@cs.wisc.edu>
Acked-by: Jayamohan Kallickal <jayamohan.kallickal@emulex.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>