Fix unused param warnings
Summary:
Compiler: GCC 7.3.1
Distro: Arch Linux
Compiler warnings:
```
/home/vlad/KDE/src/kde/workspace/kwin/effects/blur/blur.cpp: In member function ‘void KWin::BlurEffect::upscaleRenderToScreen(KWin::GLVertexBuffer*, int, int, QMatrix4x4, QRect, QPoint)’:
/home/vlad/KDE/src/kde/workspace/kwin/effects/blur/blur.cpp:677:129: warning: unused parameter ‘windowShape’ [-Wunused-parameter]
void BlurEffect::upscaleRenderToScreen(GLVertexBuffer *vbo, int vboStart, int blurRectCount, QMatrix4x4 screenProjection, QRect windowShape, QPoint windowPosition)
^~~~~~~~~~~
```
```
/home/vlad/KDE/src/kde/workspace/kwin/main_wayland.cpp: In function ‘void KWin::{anonymous}::gainRealTime(KWin::RealTimeFlags)’:
/home/vlad/KDE/src/kde/workspace/kwin/main_wayland.cpp:95:56: warning: unused parameter ‘flags’ [-Wunused-parameter]
void gainRealTime(RealTimeFlags flags = RealTimeFlags::DontReset)
```
Reviewers: #kwin, davidedmundson
Reviewed By: davidedmundson
Subscribers: anemeth, kwin
Tags: #kwin
Differential Revision: https://phabricator.kde.org/D12208
75fff17612