glcpp/tests: Add extra newline at the end of expected output.

This newline at EOF is harmless and generated by the previous commit.
diff --git a/glcpp/tests/011-define-func-empty.c.expected b/glcpp/tests/011-define-func-empty.c.expected
index 139597f..b28b04f 100644
--- a/glcpp/tests/011-define-func-empty.c.expected
+++ b/glcpp/tests/011-define-func-empty.c.expected
@@ -1,2 +1,3 @@
 
 
+