Fix unnecesary meminit

This is to fix unnecessary __meminit definition.  These are exported for
kernel modules.

I compiled on ia64/x86-64 with memory hotplug on/off.

Signed-off-by: Yasunori Goto <y-goto@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>