scsi: megaraid_sas: fix macro MEGASAS_IS_LOGICAL to avoid regression

This patch will fix regression caused by commit 1e793f6f ("scsi:
megaraid_sas: Fix data integrity failure for JBOD (passthrough)
devices").

The problem was that the MEGASAS_IS_LOGICAL macro did not have braces
and as a result the driver ended up exposing a lot of non-existing SCSI
devices (all SCSI commands to channels 1,2,3 were returned as
SUCCESS-DID_OK by driver).

[mkp: clarified patch description]

Fixes: 1e793f6f
Reported-by: Jens Axboe <axboe@kernel.dk>
CC: stable@vger.kernel.org
Signed-off-by: Kashyap Desai <kashyap.desai@broadcom.com>
Signed-off-by: Sumit Saxena <sumit.saxena@broadcom.com>
Tested-by: Sumit Saxena <sumit.saxena@broadcom.com>
Reviewed-by: Tomas Henzl <thenzl@redhat.com>
Tested-by: Jens Axboe <axboe@fb.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>