scsi: megaraid_sas: Remove IO buffer hole detection logic

As blk_queue_virt_boundary() API in slave_configure ensures that no IOs
will come with holes/gaps. Hence, code logic to detect the holes/gaps in IO
buffer is not required.

Link: https://lore.kernel.org/r/20200508083838.22778-3-chandrakanth.patil@broadcom.com
Signed-off-by: Sumit Saxena <sumit.saxena@broadcom.com>
Signed-off-by: Chandrakanth Patil <chandrakanth.patil@broadcom.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>