libyang CHANGE headers includes cleanup using include-what-you-use tool (#1098)

diff --git a/tests/utests/data/test_printer_xml.c b/tests/utests/data/test_printer_xml.c
index 16e9e5c..b36d8d5 100644
--- a/tests/utests/data/test_printer_xml.c
+++ b/tests/utests/data/test_printer_xml.c
@@ -23,6 +23,7 @@
 #include "tests/config.h"
 
 #include "../../src/context.h"
+#include "../../src/printer.h"
 #include "../../src/printer_data.h"
 
 #define BUFSIZE 1024