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>
diff --git a/lib/efi_selftest/efi_selftest.c b/lib/efi_selftest/efi_selftest.c
index 263b53f..4e5a12c 100644
--- a/lib/efi_selftest/efi_selftest.c
+++ b/lib/efi_selftest/efi_selftest.c
@@ -239,7 +239,7 @@
 	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;
 	}