x86: Fix memblock_x86_check_reserved_size() use in efi_reserve_boot_services()

The return value of memblock_x86_check_reserved_size() doesn't
indicate whether there's an overlapping reservatoin or not.  It
indicates whether the caller needs to iterate further to discover all
reserved portions of the specified area.

efi_reserve_boot_esrvices() wants to check whether the boot services
area overlaps with other reservations but incorrectly used
membloc_x86_check_reserved_size().  Use memblock_is_region_reserved()
instead.
Signed-off-by: Tejun Heo <tj@kernel.org>
Link: http://lkml.kernel.org/r/1310457490-3356-2-git-send-email-tj@kernel.org
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>

arch/x86/platform/efi/efi.c

@@ -325,8 +325,7 @@ void __init efi_reserve_boot_services(void)
 		if ((start+size >= virt_to_phys(_text)
 				&& start <= virt_to_phys(_end)) ||
 			!e820_all_mapped(start, start+size, E820_RAM) ||
-			memblock_x86_check_reserved_size(&start, &size,
-							1<<EFI_PAGE_SHIFT)) {
+			memblock_is_region_reserved(start, size)) {
 			/* Could not reserve, skip it */
 			md->num_pages = 0;
 			memblock_dbg(PFX "Could not reserve boot range "