scsi: mpt3sas: Fixed memory leaks in driver

While removing Expander devices, we are removing expander device entry
from the list before freeing its child devices. While freeing child
device we are finding its parent device node as NULL and therefore we
are not freeing the child device's allocated data structures.  Updated
the driver to remove the expander device from the list only after
freeing all its child devices.

[mkp: clarified commit message]

Signed-off-by: Sreekanth Reddy <Sreekanth.Reddy@broadcom.com>
Reviewed-by: Tomas Henzl <thenzl@redhat.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

drivers/scsi/mpt3sas/mpt3sas_scsih.c

@@ -5274,8 +5274,6 @@ mpt3sas_expander_remove(struct MPT3SAS_ADAPTER *ioc, u64 sas_address)
 	spin_lock_irqsave(&ioc->sas_node_lock, flags);
 	sas_expander = mpt3sas_scsih_expander_find_by_sas_address(ioc,
 	    sas_address);
-	if (sas_expander)
-		list_del(&sas_expander->list);
 	spin_unlock_irqrestore(&ioc->sas_node_lock, flags);
 	if (sas_expander)
 		_scsih_expander_node_remove(ioc, sas_expander);
@@ -7476,7 +7474,6 @@ _scsih_remove_unresponding_sas_devices(struct MPT3SAS_ADAPTER *ioc)
 	spin_unlock_irqrestore(&ioc->sas_node_lock, flags);
 	list_for_each_entry_safe(sas_expander, sas_expander_next, &tmp_list,
 	    list) {
-		list_del(&sas_expander->list);
 		_scsih_expander_node_remove(ioc, sas_expander);
 	}
 
@@ -8102,7 +8099,6 @@ mpt3sas_scsih_event_callback(struct MPT3SAS_ADAPTER *ioc, u8 msix_index,
  * _scsih_expander_node_remove - removing expander device from list.
  * @ioc: per adapter object
  * @sas_expander: the sas_device object
- * Context: Calling function should acquire ioc->sas_node_lock.
  *
  * Removing object and freeing associated memory from the
  * ioc->sas_expander_list.
@@ -8114,6 +8110,7 @@ _scsih_expander_node_remove(struct MPT3SAS_ADAPTER *ioc,
 	struct _sas_node *sas_expander)
 {
 	struct _sas_port *mpt3sas_port, *next;
+	unsigned long flags;
 
 	/* remove sibling ports attached to this expander */
 	list_for_each_entry_safe(mpt3sas_port, next,
@@ -8141,6 +8138,10 @@ _scsih_expander_node_remove(struct MPT3SAS_ADAPTER *ioc,
 	    sas_expander->handle, (unsigned long long)
 	    sas_expander->sas_address);
 
+	spin_lock_irqsave(&ioc->sas_node_lock, flags);
+	list_del(&sas_expander->list);
+	spin_unlock_irqrestore(&ioc->sas_node_lock, flags);
+
 	kfree(sas_expander->phy);
 	kfree(sas_expander);
 }