BGE: Fix T46381 : last action frame not updated.

It fix T46381. Normally BL_Action::Update (manage action time, end, loop…) should be called the same number of times as BL_Action::UpdateIPO (update action position, scale ect… in the game object).
But the bug report shows that UpdateIPO is called one less time than Update. To fix it i revert the commit 362b25b382 and implement a mutex in BL_Action::Update.
Example file : {F245823}

Reviewers: lordloki, kupoman, campbellbarton, youle, moguri, sybren

Reviewed By: youle, moguri, sybren

Maniphest Tasks: T39928, T46381

Differential Revision: https://developer.blender.org/D1562

source/gameengine/Ketsji/KX_GameObject.cpp

@@ -481,11 +481,6 @@ void KX_GameObject::UpdateActionManager(float curtime)
 	GetActionManager()->Update(curtime);
 }
 
-void KX_GameObject::UpdateActionIPOs()
-{
-	GetActionManager()->UpdateIPOs();
-}
-
 float KX_GameObject::GetActionFrame(short layer)
 {
 	return GetActionManager()->GetActionFrame(layer);
@@ -949,6 +944,9 @@ void KX_GameObject::InitIPO(bool ipo_as_force,
 void KX_GameObject::UpdateIPO(float curframetime,
 							  bool recurse) 
 {
+	/* This function shouldn't call BL_Action::Update, not even indirectly, 
+	 * as it will cause deadlock due to the lock in BL_Action::Update. */
+
 	// just the 'normal' update procedure.
 	GetSGNode()->SetSimulatedTime(curframetime,recurse);
 	GetSGNode()->UpdateWorldData(curframetime);