Export kallsyms_lookup_name() for kprobe/jprobe module use.

(akpm: modules which use kprobes/jrobes are usually problem-specific and
will not be merged into the mainline kernel, so we we're actually to see
actual users of this patch merged)
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>