bootmem, x86: Fix 32bit numa system without RAM on node 0

When 32bit numa is used, free_all_bootmem() will still only go over with
node id 0.

If node 0 doesn't have RAM installed, the lowest populated node
becomes low RAM.

This one fixes BOOTMEM path by iterating over the bdata_list.

-v3: add more comments, and fix bootmem path too.
-v4: seperate from one big patch
Signed-off-by: NYinghai Lu <yinghai@kernel.org>
LKML-Reference: <4BB416D7.6090203@kernel.org>
Signed-off-by: NH. Peter Anvin <hpa@zytor.com>

mm/bootmem.c

@@ -312,7 +312,13 @@ unsigned long __init free_all_bootmem(void)
 	 */
 	return free_all_memory_core_early(MAX_NUMNODES);
 #else
-	return free_all_bootmem_core(NODE_DATA(0)->bdata);
+	unsigned long total_pages = 0;
+	bootmem_data_t *bdata;
+
+	list_for_each_entry(bdata, &bdata_list, list)
+		total_pages += free_all_bootmem_core(bdata);
+
+	return total_pages;
 #endif
 }