mpt3sas: Fix use sas_is_tlr_enabled API before enabling MPI2_SCSIIO_CONTROL_TLR_ON flag

Before enabling MPI2_SCSIIO_CONTROL_TLR_ON flag in MPI SCSI IO request
message, check whether TLR is enabled on the drive using
'sas_is_tlr_enabled' API.

Actually in the driver code, driver is using below API's

1. sas_enable_tlr() - to enable the TLR
2. sas_disable_tlr() - to disable the TLR
3. sas_is_tlr_enabled() - to check whether TLR is enabled or not.

but in scsih_qcmd() we have missed to use sas_is_tlr_enabled() API,
instead we checking for TLR bit from flag field of driver's 'struct
MPT3SAS_DEVIC' structure. which is corrected with this patch.

Signed-off-by: Sreekanth Reddy <Sreekanth.Reddy@avagotech.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Tomas Henzl <thenzl@redhat.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>