Fix typos concerning hierarchy

        heirarchical, hierachical -> hierarchical
        heirarchy, hierachy -> hierarchy

Signed-off-by: Uwe Kleine-König <zeisberg@informatik.uni-freiburg.de>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
diff --git a/drivers/scsi/scsi_transport_sas.c b/drivers/scsi/scsi_transport_sas.c
index 6d39150e..b2ef71a 100644
--- a/drivers/scsi/scsi_transport_sas.c
+++ b/drivers/scsi/scsi_transport_sas.c
@@ -500,7 +500,7 @@
 EXPORT_SYMBOL(sas_phy_alloc);
 
 /**
- * sas_phy_add  --  add a SAS PHY to the device hierachy
+ * sas_phy_add  --  add a SAS PHY to the device hierarchy
  * @phy:	The PHY to be added
  *
  * Publishes a SAS PHY to the rest of the system.
@@ -1265,7 +1265,7 @@
 EXPORT_SYMBOL(sas_expander_alloc);
 
 /**
- * sas_rphy_add  --  add a SAS remote PHY to the device hierachy
+ * sas_rphy_add  --  add a SAS remote PHY to the device hierarchy
  * @rphy:	The remote PHY to be added
  *
  * Publishes a SAS remote PHY to the rest of the system.