Fix build on older GCC versions

Travis builds would fail with:
./drivers/gles3/rasterizer_storage_gles3.h:1018:19: error: ISO C++ forbids initialization of member 'fixed_fps' [-fpermissive]

drivers/gles3/rasterizer_storage_gles3.h

@@ -1015,7 +1015,7 @@ public:
 
 		uint32_t cycle_number;
 
-		int fixed_fps = 0;
+		int fixed_fps;
 		bool fractional_delta;
 		float frame_remainder;
 

scene/2d/canvas_item.cpp

@@ -682,9 +682,7 @@ Vector2 CanvasItem::make_canvas_pos_local(const Vector2 &screen_point) const {
 
 	ERR_FAIL_COND_V(!is_inside_tree(), screen_point);
 
-	Transform2D local_matrix = (get_canvas_transform() *
-									   get_global_transform())
-									   .affine_inverse();
+	Transform2D local_matrix = (get_canvas_transform() * get_global_transform()).affine_inverse();
 
 	return local_matrix.xform(screen_point);
 }