firmware_map: make firmware_map_add_early() argument consistent with firmware_map_add_hotplug()

There are two ways to create /sys/firmware/memmap/X sysfs:

  - firmware_map_add_early
    When the system starts, it is calledd from e820_reserve_resources()
  - firmware_map_add_hotplug
    When the memory is hot plugged, it is called from add_memory()

But these functions are called without unifying value of end argument as
below:

  - end argument of firmware_map_add_early()   : start + size - 1
  - end argument of firmware_map_add_hogplug() : start + size

The patch unifies them to "start + size".  Even if applying the patch,
/sys/firmware/memmap/X/end file content does not change.

[akpm@linux-foundation.org: clarify comments]
Signed-off-by: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Reviewed-by: Dave Hansen <dave@linux.vnet.ibm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

arch/x86/kernel/e820.c

@@ -944,7 +944,7 @@ void __init e820_reserve_resources(void)
 	for (i = 0; i < e820_saved.nr_map; i++) {
 		struct e820entry *entry = &e820_saved.map[i];
 		firmware_map_add_early(entry->addr,
-			entry->addr + entry->size - 1,
+			entry->addr + entry->size,
 			e820_type_to_string(entry->type));
 	}
 }