Shrinks the only caller (net/bridge/netfilter/ebtables.c) by 174 bytes.

Also, optimise highest_possible_processor_id() out of existence on
CONFIG_SMP=n.

Cc: Paul Jackson <pj@sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>