Use a QFunctionPointer for getProcAddress()

qdoc does not understand the void (*) syntax, there is a typedef to
QFunctionPointer that does work.

Change-Id: Idbe9d43d00f8676304d088d72795b6ddb7e4ee72
Reviewed-by: Samuel Rødal <samuel.rodal@nokia.com>

src/gui/kernel/qplatformopenglcontext_qpa.cpp

@@ -65,25 +65,18 @@ QT_BEGIN_NAMESPACE
     which maps to the QPlatformOpenGLContext.
 */
 
-/*! \fn void QPlatformOpenGLContext::swapBuffers()
+/*! \fn void QPlatformOpenGLContext::swapBuffers(QPlatformSurface *surface)
     Reimplement in subclass to native swap buffers calls
 
     The implementation must support being called in a thread different than the gui-thread.
 */
 
-/*! \fn void *QPlatformOpenGLContext::getProcAddress(const QString &procName)
+/*! \fn QFunctionPointer QPlatformOpenGLContext::getProcAddress(const QByteArray &procName)
     Reimplement in subclass to native getProcAddr calls.
 
     Note: its convenient to use qPrintable(const QString &str) to get the const char * pointer
 */
 
-/*! \fn QPlatformWindowFormat QPlatformOpenGLContext::platformWindowFormat() const
-    QWidget has the function qplatformWindowFormat(). That function is for the application
-    programmer to request the format of the window and the context that he wants.
-
-    Reimplement this function in a subclass to indicate what format the glContext actually has.
-*/
-
 class QPlatformOpenGLContextPrivate
 {
 public:

src/gui/kernel/qplatformopenglcontext_qpa.h

@@ -68,7 +68,7 @@ public:
     virtual bool makeCurrent(QPlatformSurface *surface) = 0;
     virtual void doneCurrent() = 0;
 
-    virtual void (*getProcAddress(const QByteArray &procName)) () = 0;
+    virtual QFunctionPointer getProcAddress(const QByteArray &procName) = 0;
 
     QOpenGLContext *context() const;