mm: enable set_page_section() only if CONFIG_SPARSEMEM and !CONFIG_SPARSEMEM_VMEMMAP
set_page_section() is meaningful only in CONFIG_SPARSEMEM and
!CONFIG_SPARSEMEM_VMEMMAP context. Move it to proper place and amend
accordingly functions which are using it.
Signed-off-by: Daniel Kiper <dkiper@net-space.pl> Acked-by: Dave Hansen <dave@linux.vnet.ibm.com> Acked-by: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>