x86, mm: Move min_pfn_mapped back to mm/init.c

Also change it to static.

Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Link: http://lkml.kernel.org/r/1353123563-3103-26-git-send-email-yinghai@kernel.org
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>

arch/x86/mm/init.c

@@ -23,6 +23,8 @@ unsigned long __initdata pgt_buf_start;
 unsigned long __meminitdata pgt_buf_end;
 unsigned long __meminitdata pgt_buf_top;
 
+static unsigned long min_pfn_mapped;
+
 __ref void *alloc_low_page(void)
 {
 	unsigned long pfn;