mm: remove sparsemem allocation details from the bootmem allocator

mm: remove sparsemem allocation details from the bootmem allocator

alloc_bootmem_section() derives allocation area constraints from the
specified sparsemem section.  This is a bit specific for a generic memory
allocator like bootmem, though, so move it over to sparsemem.

As __alloc_bootmem_node_nopanic() already retries failed allocations with
relaxed area constraints, the fallback code in sparsemem.c can be removed
and the code becomes a bit more compact overall.

[[email protected]: fix build]
Signed-off-by: Johannes Weiner <[email protected]>
Acked-by: Tejun Heo <[email protected]>
Acked-by: David S. Miller <[email protected]>
Cc: Yinghai Lu <[email protected]>
Cc: Gavin Shan <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>