[SCSI] libsas: delete device on sas address changed

If the phy is attached to a new sas address unregister the first address
before processing the new attachment.

Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
diff --git a/drivers/scsi/libsas/sas_expander.c b/drivers/scsi/libsas/sas_expander.c
index 7e2d3c4..d63f0fb 100644
--- a/drivers/scsi/libsas/sas_expander.c
+++ b/drivers/scsi/libsas/sas_expander.c
@@ -2005,6 +2005,15 @@
 		return res;
 	}
 
+	/* delete the old link */
+	if (SAS_ADDR(phy->attached_sas_addr) &&
+	    SAS_ADDR(sas_addr) != SAS_ADDR(phy->attached_sas_addr)) {
+		SAS_DPRINTK("ex %016llx phy 0x%x replace %016llx\n",
+			    SAS_ADDR(dev->sas_addr), phy_id,
+			    SAS_ADDR(phy->attached_sas_addr));
+		sas_unregister_devs_sas_addr(dev, phy_id, last);
+	}
+
 	return sas_discover_new(dev, phy_id);
 }