MDL-26416 quiz overview report, clean up the code before making the real bug fix.

Cleaning up the code like this will make the real bug-fix easier to understand.

mod/quiz/report/overview/report.php

@@ -202,18 +202,25 @@ class quiz_overview_report extends quiz_default_report {
         if (!$nostudents || ($attemptsmode == QUIZ_REPORT_ATTEMPTS_ALL)) {
 
             // Construct the SQL
-            $fields = $DB->sql_concat('u.id', '\'#\'', 'COALESCE(qa.attempt, 0)').' AS uniqueid, ';
+            $fields = $DB->sql_concat('u.id', "'#'", 'COALESCE(qa.attempt, 0)') . ' AS uniqueid,';
             if ($qmsubselect) {
-                $fields .=
-                    "(CASE " .
-                    "   WHEN $qmsubselect THEN 1" .
-                    "   ELSE 0 " .
-                    "END) AS gradedattempt, ";
+                $fields .= "\n(CASE WHEN $qmsubselect THEN 1 ELSE 0 END) AS gradedattempt,";
             }
 
-            $fields .='qa.uniqueid AS attemptuniqueid, qa.id AS attempt, ' .
-                'u.id AS userid, u.idnumber, u.firstname, u.lastname, u.picture, u.imagealt, u.email, '.
-                'qa.sumgrades, qa.timefinish, qa.timestart, qa.timefinish - qa.timestart AS duration ';
+            $fields .= '
+                    qa.uniqueid AS attemptuniqueid,
+                    qa.id AS attempt,
+                    u.id AS userid,
+                    u.idnumber,
+                    u.firstname,
+                    u.lastname,
+                    u.picture,
+                    u.imagealt,
+                    u.email,
+                    qa.sumgrades,
+                    qa.timefinish,
+                    qa.timestart,
+                    qa.timefinish - qa.timestart AS duration';
 
             // This part is the same for all cases - join users and quiz_attempts tables
             $from = '{user} u ';