signalfd-add-ability-to-return-siginfo-in-a-raw-format-v2-fix

signalfd-add-ability-to-return-siginfo-in-a-raw-format-v2-fix

fix __user annotations, tidy comments and code layout

Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Andrey Vagin <avagin@openvz.org>
Cc: Cyrill Gorcunov <gorcunov@openvz.org>
Cc: David Howells <dhowells@redhat.com>
Cc: Michael Kerrisk <mtk.manpages@gmail.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Pavel Emelyanov <xemul@parallels.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Michael Kerrisk <mtk.manpages@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>