Remove Q_INIT_RESOURCE_EXTERN

It's not providing any convenience over using Q_INIT_RESOURCE, which does
its own extern, were never documented, and was added back in 2010 without
any commit message justifying its existence.

Change-Id: I1ca9a042d3f4fca34007d28b140661c50064f11b
Reviewed-by: Simon Hausmann <simon.hausmann@digia.com>
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
Reviewed-by: Oswald Buddenhagen <oswald.buddenhagen@digia.com>

src/corelib/global/qglobal.h

@@ -326,9 +326,6 @@ typedef double qreal;
 #    define Q_AUTOTEST_EXPORT
 #endif
 
-#define Q_INIT_RESOURCE_EXTERN(name) \
-    extern int QT_MANGLE_NAMESPACE(qInitResources_ ## name) ();
-
 #define Q_INIT_RESOURCE(name) \
     do { extern int QT_MANGLE_NAMESPACE(qInitResources_ ## name) ();       \
         QT_MANGLE_NAMESPACE(qInitResources_ ## name) (); } while (0)

src/plugins/platforms/cocoa/qcocoaintegration.mm

@@ -63,7 +63,6 @@
 
 static void initResources()
 {
-    Q_INIT_RESOURCE_EXTERN(qcocoaresources)
     Q_INIT_RESOURCE(qcocoaresources);
 }
 

src/widgets/kernel/qapplication.cpp

@@ -111,13 +111,10 @@ extern bool qt_wince_is_pocket_pc();  //qguifunctions_wince.cpp
 static void initResources()
 {
 #if defined(Q_OS_WINCE)
-    Q_INIT_RESOURCE_EXTERN(qstyle_wince)
     Q_INIT_RESOURCE(qstyle_wince);
 #else
-    Q_INIT_RESOURCE_EXTERN(qstyle)
     Q_INIT_RESOURCE(qstyle);
 #endif
-    Q_INIT_RESOURCE_EXTERN(qmessagebox)
     Q_INIT_RESOURCE(qmessagebox);
 
 }