add missing semicolon

Author: acxz

src/lib/stats.js

@@ -50,7 +50,7 @@ exports.mean = function(data, len) {
 exports.geometricMean = function(data, len) {
     if(!len) len = exports.len(data);
     return Math.pow(exports.aggNums(function(a, b) { return a * b; }, 1, data), 1 / len);
-}
+};
 
 exports.midRange = function(numArr) {
     if(numArr === undefined || numArr.length === 0) return undefined;