Remove unnecessary argument to hover call

Author: mdtusz

src/traces/pie/index.js

@@ -363,7 +363,7 @@ pie.plot = function(gd, cdpie) {
                         }
                     );
 
-                    Plotly.Fx.hover(gd, evt, 'pie');
+                    Plotly.Fx.hover(gd, evt);
 
                     hasHoverData = true;
                 }