use $data in sma()

Author: adriangibbons

src/phpFITFileAnalysis.php

@@ -1684,7 +1684,7 @@ private function sma($array, $time_period)
         $count = count($array);
 
         for ($i=0; $i<$count-$time_period; ++$i) {
-            $sma_data[] = array_sum(array_slice($array, $i, $time_period)) / $time_period;
+            $sma_data[] = array_sum(array_slice($data, $i, $time_period)) / $time_period;
         }
 
         return $sma_data;