Remove unnessecary assignement

https://lgtm.com/projects/g/mrdoob/three.js/snapshot/88225c1a6d4bcdcf2ab408a972a8319ff38f4f53/files/examples/js/loaders/FBXLoader.js#V1099

examples/js/loaders/FBXLoader.js

@@ -1098,8 +1098,6 @@
 				}
 
 				polygonIndex ++;
-
-				endOfFace = false;
 				faceLength = 0;
 
 				// reset arrays for the next face