regradeAll: refer to correct submissions variable
regradeAll: refer to correct submissions variable

Fix misuse of @submission in regradeAll and regradeBatch

cg2v/Autolab,cg2v/Autolab,autolab/Autolab,cg2v/Autolab,cg2v/Autolab,autolab/Autolab,autolab/Autolab,cg2v/Autolab,autolab/Autolab,autolab/Autolab,autolab/Autolab,cg2v/Autolab