x86: remove end_pfn in 64bit

and use max_pfn directly.

Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/arch/x86/kernel/e820.c b/arch/x86/kernel/e820.c
index 1b76b25..3900ff5 100644
--- a/arch/x86/kernel/e820.c
+++ b/arch/x86/kernel/e820.c
@@ -527,7 +527,7 @@
 
 #ifdef CONFIG_X86_64
 	if (!found) {
-		gapstart = (end_pfn << PAGE_SHIFT) + 1024*1024;
+		gapstart = (max_pfn << PAGE_SHIFT) + 1024*1024;
 		printk(KERN_ERR "PCI: Warning: Cannot find a gap in the 32bit "
 		       "address range\n"
 		       KERN_ERR "PCI: Unassigned devices with 32bit resource "