Change var endIndex to lastIndex for source consistency.

lodash.src.js

@@ -10108,13 +10108,13 @@
 
       var index = -1,
           length = path.length,
-          endIndex = length - 1,
+          lastIndex = length - 1,
           nested = object;
 
       while (nested != null && ++index < length) {
         var key = path[index];
         if (isObject(nested)) {
-          if (index == endIndex) {
+          if (index == lastIndex) {
             nested[key] = value;
           } else if (nested[key] == null) {
             nested[key] = isIndex(path[index + 1]) ? [] : {};