efi_selftest: add missing line feed

Add a missing line feed for an error message.

Reviewed-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
Signed-off-by: Alexander Graf <agraf@suse.de>

lib/efi_selftest/efi_selftest.c

@@ -239,7 +239,7 @@ efi_status_t EFIAPI efi_selftest(efi_handle_t image_handle,
 	ret = boottime->handle_protocol(image_handle, &efi_guid_loaded_image,
 					(void **)&loaded_image);
 	if (ret != EFI_SUCCESS) {
-		efi_st_error("Cannot open loaded image protocol");
+		efi_st_error("Cannot open loaded image protocol\n");
 		return ret;
 	}