microblaze: no need to reset handler if SA_ONESHOT

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>
Acked-by: Michal Simek <monstr@monstr.eu>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>