x86: rename two e820 related functions

rename update_memory_range to e820_update_range
rename add_memory_region to e820_add_region

to make it more clear that they are about e820 map operations.

Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/arch/x86/lguest/boot.c b/arch/x86/lguest/boot.c
index 5e47729..e72cf07 100644
--- a/arch/x86/lguest/boot.c
+++ b/arch/x86/lguest/boot.c
@@ -835,7 +835,7 @@
 
 	/* The Linux bootloader header contains an "e820" memory map: the
 	 * Launcher populated the first entry with our memory limit. */
-	add_memory_region(boot_params.e820_map[0].addr,
+	e820_add_region(boot_params.e820_map[0].addr,
 			  boot_params.e820_map[0].size,
 			  boot_params.e820_map[0].type);