Remove second row caused by WITH ROLLUP

Remove second row caused by WITH ROLLUP

I need to remove the 2nd row of results which contain a duplicate of the
total record from the 1st row. My result set is as follows
1 | 1025
1 | NULL --- I need to remove this row
My query is as follows:
SELECT SUM( mdl_quiz.fcpd ) AS cpdtotal, mdl_user.id AS userid
FROM mdl_grade_grades
INNER JOIN mdl_user ON mdl_grade_grades.userid = mdl_user.id
INNER JOIN mdl_grade_items ON mdl_grade_grades.itemid = mdl_grade_items.id
INNER JOIN mdl_quiz ON mdl_grade_items.itemname = mdl_quiz.name
INNER JOIN mdl_course ON mdl_grade_items.courseid = mdl_course.id
INNER JOIN mdl_user_info_data ON mdl_user.id = mdl_user_info_data.userid
WHERE mdl_user_info_data.fieldid =1
AND mdl_grade_items.itemname IS NOT NULL
AND mdl_user.annualCPDReportActive = 'Y'
AND (
mdl_course.category =27
)
AND mdl_user.id =1025
AND YEAR( FROM_UNIXTIME( mdl_grade_grades.timemodified ) ) =2013
GROUP BY mdl_user.id
WITH ROLLUP