sched, sparc32: Update scheduler comments in copy_thread()
There's no finish_arch_switch() anymore in the latest scheduler tree.
Also update some other details.
Cc: David S. Miller <davem@davemloft.net> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Cc: sparclinux@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>