efi_loader: use EfiBootServicesData for device path

dp_alloc() was using a constant from the wrong enum resulting in creating
device paths in EfiReservedMemory.

Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>
diff --git a/lib/efi_loader/efi_device_path.c b/lib/efi_loader/efi_device_path.c
index 9c3ac71..cbdb466 100644
--- a/lib/efi_loader/efi_device_path.c
+++ b/lib/efi_loader/efi_device_path.c
@@ -68,7 +68,7 @@
 {
 	void *buf;
 
-	if (efi_allocate_pool(EFI_ALLOCATE_ANY_PAGES, sz, &buf) !=
+	if (efi_allocate_pool(EFI_BOOT_SERVICES_DATA, sz, &buf) !=
 	    EFI_SUCCESS) {
 		debug("EFI: ERROR: out of memory in %s\n", __func__);
 		return NULL;