Remove Placement* member variable from Workspace

Not needed anymore given that Placement became a singleton.

REVIEW: 107416

workspace.cpp

@@ -374,7 +374,7 @@ void Workspace::init()
     m_desktopFocusChain = m_activitiesDesktopFocusChain.insert(QString(), QVector<int>(numberOfDesktops()));
 
     // Now we know how many desktops we'll have, thus we initialize the positioning object
-    initPositioning = Placement::create(this);
+    Placement::create(this);
 
     loadDesktopSettings();
     updateDesktopLayout();
@@ -546,7 +546,7 @@ Workspace::~Workspace()
     delete supportWindow;
     delete mgr;
     delete startup;
-    delete initPositioning;
+    delete Placement::self();
     delete client_keys_dialog;
     while (!rules.isEmpty()) {
         delete rules.front();
@@ -1640,7 +1640,7 @@ void Workspace::setNumberOfDesktops(int n)
         return;
     int old_number_of_desktops = numberOfDesktops();
     desktopCount_ = n;
-    initPositioning->reinitCascading(0);
+    Placement::self()->reinitCascading(0);
     updateDesktopLayout(); // Make sure the layout is still valid
 
     if (currentDesktop() > n)

workspace.h

@@ -73,7 +73,6 @@ class Client;
 class Outline;
 class RootInfo;
 class PluginMgr;
-class Placement;
 class Rules;
 class Scripting;
 class UserActionsMenu;
@@ -828,8 +827,6 @@ private:
 
     KStartupInfo* startup;
 
-    Placement* initPositioning;
-
     QVector<QRect> workarea; // Array of workareas for virtual desktops
     // Array of restricted areas that window cannot be moved into
     QVector<StrutRects> restrictedmovearea;