Remove the GL_QUADS_KWIN definition

GL_QUADS is always defined now that we're using libepoxy.

libkwineffects/kwinglutils_funcs.h

@@ -37,8 +37,6 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
 #include <epoxy/gl.h>
 
-#define GL_QUADS_KWIN 0x0007
-
 namespace KWin
 {
 

scene_opengl.cpp

@@ -1080,7 +1080,7 @@ void SceneOpenGL::Window::renderQuads(int, const QRegion& region, const WindowQu
     int primcount;
 
     if (GLVertexBuffer::supportsIndexedQuads()) {
-        primitiveType = GL_QUADS_KWIN;
+        primitiveType = GL_QUADS;
         primcount = quads.count() * 4;
     } else {
         primitiveType = GL_TRIANGLES;
@@ -1242,7 +1242,7 @@ void SceneOpenGL2Window::performPaint(int mask, QRegion region, WindowPaintData
     }
 
     const bool indexedQuads = GLVertexBuffer::supportsIndexedQuads();
-    const GLenum primitiveType = indexedQuads ? GL_QUADS_KWIN : GL_TRIANGLES;
+    const GLenum primitiveType = indexedQuads ? GL_QUADS : GL_TRIANGLES;
     const int verticesPerQuad = indexedQuads ? 4 : 6;
 
     const size_t size = verticesPerQuad *