From: Bodo Stroesser <bstroesser@fujitsu-siemens.com>

In most cases reboot failed on my system.  After "Restarting system.", UML
exited without further messages.  I found an SIGIO being processed by
sig_handler() resp.  sig_handler_common_skas().  Don't know, why this exits,
maybe the context is no longer valid at this time.  So, I changed the sequence
in the reboot part of main() to stop the timers and disable the fds before
unblocking the signals.  Since this wasn't enough, I also added
set_handler(SIGXXX, SIG_IGN) calls to disable_timer() and
deactivate_all_fds().  Now reboot works fine in SKAS and it still works in TT.
Signed-off-by: Bodo Stroesser <bstroesser@fujitsu-siemens.com>
Signed-off-by: Jeff Dike <jdike@addtoit.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>