[core] Avoid calling virtual GeometryTile::cancel() on dtor

warning: Call to virtual function during destruction will not dispatch
to derived class [clang-analyzer-optin.cplusplus.VirtualCall]

src/mbgl/tile/geometry_tile.cpp

@@ -47,10 +47,14 @@ GeometryTile::GeometryTile(const OverscaledTileID& id_,
 GeometryTile::~GeometryTile() {
     glyphAtlas.removeGlyphs(*this);
     spriteAtlas.removeRequestor(*this);
-    cancel();
+    markObsolete();
 }
 
 void GeometryTile::cancel() {
+    markObsolete();
+}
+
+void GeometryTile::markObsolete() {
     obsolete = true;
 }
 

src/mbgl/tile/geometry_tile.hpp

@@ -87,6 +87,8 @@ protected:
     }
 
 private:
+    void markObsolete();
+
     const std::string sourceID;
     style::Style& style;