GL: use the more explicit initializer list to ArrayView conversion here.

This code got made long before this helper was a thing.

src/Magnum/GL/Buffer.h

@@ -1174,7 +1174,7 @@ class MAGNUM_GL_EXPORT Buffer: public AbstractObject {
          * @m_since{2019,10}
          */
         template<class T> Buffer& setData(std::initializer_list<T> data, BufferUsage usage = BufferUsage::StaticDraw) {
-            return setData({data.begin(), data.size()}, usage);
+            return setData(Containers::arrayView(data), usage);
         }
 
         /**
@@ -1196,7 +1196,7 @@ class MAGNUM_GL_EXPORT Buffer: public AbstractObject {
          * @m_since{2019,10}
          */
         template<class T> Buffer& setSubData(GLintptr offset, std::initializer_list<T> data) {
-            return setSubData(offset, {data.begin(), data.size()});
+            return setSubData(offset, Containers::arrayView(data));
         }
 
         /**