printers CHANGE provide error information from ly_out constructors

Provide specific LY_ERR value to inform what failed when creating
ly_out structure.
diff --git a/tests/utests/data/test_parser_xml.c b/tests/utests/data/test_parser_xml.c
index e81a3f0..460eaa0 100644
--- a/tests/utests/data/test_parser_xml.c
+++ b/tests/utests/data/test_parser_xml.c
@@ -178,7 +178,7 @@
     struct lyd_node *tree;
 
     struct ly_out *out;
-    assert_non_null(out = ly_out_new_memory(&str, 0));
+    assert_int_equal(LY_SUCCESS, ly_out_new_memory(&str, 0, &out));
 
     data =
     "<any xmlns=\"urn:tests:a\">"
@@ -327,7 +327,7 @@
     struct lyd_node *tree;
 
     struct ly_out *out;
-    assert_non_null(out = ly_out_new_memory(&str, 0));
+    assert_int_equal(LY_SUCCESS, ly_out_new_memory(&str, 0, &out));
 
     /* invalid value, no flags */
     data = "<foo3 xmlns=\"urn:tests:a\"/>";
@@ -404,7 +404,7 @@
     const struct lyd_node *node;
 
     struct ly_out *out;
-    assert_non_null(out = ly_out_new_memory(&str, 0));
+    assert_int_equal(LY_SUCCESS, ly_out_new_memory(&str, 0, &out));
 
     data =
         "<rpc xmlns=\"urn:ietf:params:xml:ns:netconf:base:1.0\" msgid=\"25\" custom-attr=\"val\">"
@@ -490,7 +490,7 @@
     const struct lyd_node *node;
 
     struct ly_out *out;
-    assert_non_null(out = ly_out_new_memory(&str, 0));
+    assert_int_equal(LY_SUCCESS, ly_out_new_memory(&str, 0, &out));
 
     data =
         "<rpc xmlns=\"urn:ietf:params:xml:ns:netconf:base:1.0\" msgid=\"25\" custom-attr=\"val\">"
@@ -549,7 +549,7 @@
     const struct lyd_node *node;
 
     struct ly_out *out;
-    assert_non_null(out = ly_out_new_memory(&str, 0));
+    assert_int_equal(LY_SUCCESS, ly_out_new_memory(&str, 0, &out));
 
     data =
         "<notification xmlns=\"urn:ietf:params:xml:ns:netconf:notification:1.0\">"
@@ -617,7 +617,7 @@
     const struct lyd_node *node;
 
     struct ly_out *out;
-    assert_non_null(out = ly_out_new_memory(&str, 0));
+    assert_int_equal(LY_SUCCESS, ly_out_new_memory(&str, 0, &out));
 
     data =
         "<c xmlns=\"urn:tests:a\">"