Commit 2f4dfe206a2fc07099dfad77a8ea2f4b4ae2140f moved the definition
of hard_smp_processor_id() for the UP case from include/linux/smp.h
to include/asm/smp.h. However, include/linux/smp.h only includes
include/asm/smp.h in the SMP case, so code that wants to use
hard_smp_processor_id() has to include <asm/smp.h> explicitly to
be sure of getting the definition.
Signed-off-by: Paul Mackerras <paulus@samba.org>