kfree(NULL) is valid.
pointed out by checkpatch.pl.
the fix shrinks the code a bit:
   text    data     bss     dec     hex filename
  40024    3842     100   43966    abbe sched.o.before
  40002    3842     100   43944    aba8 sched.o.after
Signed-off-by: Ingo Molnar <mingo@elte.hu>
 
 err:
        for_each_possible_cpu(i) {
-               if (tg->cfs_rq && tg->cfs_rq[i])
+               if (tg->cfs_rq)
                        kfree(tg->cfs_rq[i]);
-               if (tg->se && tg->se[i])
+               if (tg->se)
                        kfree(tg->se[i]);
        }
-       if (tg->cfs_rq)
-               kfree(tg->cfs_rq);
-       if (tg->se)
-               kfree(tg->se);
-       if (tg)
-               kfree(tg);
+       kfree(tg->cfs_rq);
+       kfree(tg->se);
+       kfree(tg);
 
        return ERR_PTR(-ENOMEM);
 }