[SCSI] mpt2sas: move the scsi_host_put to the right place

When scsi_add_host fails the scsi_host_put should be called.

Signed-off-by: Tomas Henzl <thenzl@redhat.com>
Acked-by: "Nandigama, Nagalakshmi" <Nagalakshmi.Nandigama@lsi.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>