get_signal_to_deliver() already resets the signal handler if
SA_ONESHOT is set in ka->sa.sa_flags, there's no need to do it again
in handle_signal(). Furthermore, because we were modifying
ka->sa.sa_handler (which is a copy of sighand->action[]) instead of
sighand->action[] the original code actually had no effect on signal
delivery.
Acked-by: Oleg Nesterov <oleg@redhat.com> Cc: Jonas Bonn <jonas@southpole.se> Cc: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Matt Fleming <matt.fleming@intel.com> Signed-off-by: Oleg Nesterov <oleg@redhat.com>