Fix a couple of warnings

engine/resource/FontResource.h

@@ -168,6 +168,7 @@ public:
 		}
 
 		CE_FATAL("Glyph not found");
+		return FontGlyphData();
 	}
 
 private:

engine/resource/UnitResource.cpp

@@ -83,6 +83,7 @@ uint32_t compute_link_depth(const GraphNode& node, const Array<GraphNode>& nodes
 	}
 
 	CE_FATAL("Node not found");
+	return 0;
 }
 
 //-----------------------------------------------------------------------------