sched/autogroup: Fix sysctl move

Ivan reported /proc/sys/kernel/sched_autogroup_enabled went walk-about
and using the noautogroup command line parameter would result in a
boot error message.

Turns out the sysctl move placed the init function wrong.

Fixes: c8eaf6ac ("sched: move autogroup sysctls into its own file")
Reported-by: Ivan Kozik <ivan@ludios.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Ivan Kozik <ivan@ludios.org>
Link: https://lkml.kernel.org/r/YpR2IqndgsyMzN00@worktop.programming.kicks-ass.net