[PATCH] Update sysrq-B to use emergency_restart()

sysrq calls into the reboot path from an interrupt handler
we can either push the code do into process context and
call kernel_restart and get a clean reboot or we can simply
reboot the machine, and increase our chances of actually
rebooting.  emergency_reboot() seems like the closest match
to what we have previously done, and what we want.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>