mm: pass the vmem_altmap to vmemmap_populate

We can just pass this on instead of having to do a radix tree lookup
without proper locking a few levels into the callchain.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

arch/s390/mm/vmem.c

@@ -211,7 +211,8 @@ static void vmem_remove_range(unsigned long start, unsigned long size)
 /*
  * Add a backed mem_map array to the virtual mem_map array.
  */
-int __meminit vmemmap_populate(unsigned long start, unsigned long end, int node)
+int __meminit vmemmap_populate(unsigned long start, unsigned long end, int node,
+		struct vmem_altmap *altmap)
 {
 	unsigned long pgt_prot, sgt_prot;
 	unsigned long address = start;