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/kernel/efi.c b/arch/x86/kernel/efi.c
index d5c7fcd..473c89f 100644
--- a/arch/x86/kernel/efi.c
+++ b/arch/x86/kernel/efi.c
@@ -233,7 +233,7 @@
 			e820_type = E820_RAM;
 		else
 			e820_type = E820_RESERVED;
-		add_memory_region(start, size, e820_type);
+		e820_add_region(start, size, e820_type);
 	}
 	sanitize_e820_map(e820.map, ARRAY_SIZE(e820.map), &e820.nr_map);
 }