[SCSI] mptfusion: Check for command status is added after completion.

1) Corrected name string as "MPT SAS HOST"
2) Added proper check conditions for MPT_MGMT_STATUS_COMMAND_GOOD.

Signed-off-by: Kashyap Desai <kashyap.desai@lsi.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>