Fixed regression throwing fatal error with honeycomb infill

lib/Slic3r/Fill/Honeycomb.pm

@@ -39,7 +39,7 @@ sub fill_surface {
         
         # adjust actual bounding box to the nearest multiple of our hex pattern
         # and align it so that it matches across layers
-        my $bounding_box = [ 0, 0, $self->print->x_length, $self->print->y_length ];
+        my $bounding_box = [ 0, 0, $self->print->total_x_length, $self->print->total_y_length ];
         {
             my $bb_polygon = Slic3r::Polygon->new([
                 [ $bounding_box->[X1], $bounding_box->[Y1] ],