aa953877 removed the implementation of
lock_cpu_hotplug_interruptible and all users of it.  This stub definition
for !CONFIG_HOTPLUG_CPU was left over -- kill it now.
Signed-off-by: NNathan Lynch <ntl@pobox.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>