tests CHANGE headers includes cleanup

Set necessary include directories instead of including library headers
in tests via relative path (which cause problems when building in
some nonstandard build directories).
diff --git a/tests/utests/schema/test_parser_yang.c b/tests/utests/schema/test_parser_yang.c
index 31b9c34..c51bafe 100644
--- a/tests/utests/schema/test_parser_yang.c
+++ b/tests/utests/schema/test_parser_yang.c
@@ -20,10 +20,10 @@
 #include <stdio.h>
 #include <string.h>
 
-#include "../../../src/common.h"
-#include "../../../src/tree_schema.h"
-#include "../../../src/tree_schema_internal.h"
-#include "../../../src/parser_internal.h"
+#include "common.h"
+#include "parser_internal.h"
+#include "tree_schema.h"
+#include "tree_schema_internal.h"
 
 /* originally static functions from tree_schema_free.c and parser_yang.c */
 void lysp_ext_instance_free(struct ly_ctx *ctx, struct lysp_ext_instance *ext);
diff --git a/tests/utests/schema/test_parser_yin.c b/tests/utests/schema/test_parser_yin.c
index d2576b9..737d2d5 100644
--- a/tests/utests/schema/test_parser_yin.c
+++ b/tests/utests/schema/test_parser_yin.c
@@ -21,13 +21,13 @@
 #include <string.h>
 #include <stdbool.h>
 
-#include "../../../src/common.h"
-#include "../../../src/tree_schema.h"
-#include "../../../src/tree_schema_internal.h"
-#include "../../../src/parser_internal.h"
-#include "../../../src/parser_yin.h"
-#include "../../../src/xml.h"
-#include "../../../src/xpath.h"
+#include "common.h"
+#include "parser_internal.h"
+#include "parser_yin.h"
+#include "tree_schema.h"
+#include "tree_schema_internal.h"
+#include "xml.h"
+#include "xpath.h"
 
 /* prototypes of static functions */
 void lysp_ext_instance_free(struct ly_ctx *ctx, struct lysp_ext_instance *ext);
diff --git a/tests/utests/schema/test_printer_yang.c b/tests/utests/schema/test_printer_yang.c
index feea18e..24e8b31 100644
--- a/tests/utests/schema/test_printer_yang.c
+++ b/tests/utests/schema/test_printer_yang.c
@@ -20,9 +20,9 @@
 #include <stdio.h>
 #include <string.h>
 
-#include "../../src/context.h"
-#include "../../src/printer.h"
-#include "../../src/printer_schema.h"
+#include "context.h"
+#include "printer.h"
+#include "printer_schema.h"
 
 #define BUFSIZE 1024
 char logbuf[BUFSIZE] = {0};
diff --git a/tests/utests/schema/test_printer_yin.c b/tests/utests/schema/test_printer_yin.c
index 8a1fee9..2d82f88 100644
--- a/tests/utests/schema/test_printer_yin.c
+++ b/tests/utests/schema/test_printer_yin.c
@@ -21,9 +21,9 @@
 #include <stdlib.h>
 #include <string.h>
 
-#include "../../src/context.h"
-#include "../../src/printer.h"
-#include "../../src/printer_schema.h"
+#include "context.h"
+#include "printer.h"
+#include "printer_schema.h"
 
 #define BUFSIZE 1024
 char logbuf[BUFSIZE] = {0};
diff --git a/tests/utests/schema/test_schema.c b/tests/utests/schema/test_schema.c
index ffb7195..9a03332 100644
--- a/tests/utests/schema/test_schema.c
+++ b/tests/utests/schema/test_schema.c
@@ -22,9 +22,9 @@
 
 #include <string.h>
 
-#include "config.h"
 #include "log.h"
 #include "parser_schema.h"
+#include "tests/config.h"
 #include "tree_schema.h"
 
 #if ENABLE_LOGGER_CHECKING
diff --git a/tests/utests/schema/test_schema.h b/tests/utests/schema/test_schema.h
index b6f1929..d0212fb 100644
--- a/tests/utests/schema/test_schema.h
+++ b/tests/utests/schema/test_schema.h
@@ -14,9 +14,9 @@
 #ifndef TESTS_UTESTS_SCHEMA_TEST_SCHEMA_H_
 #define TESTS_UTESTS_SCHEMA_TEST_SCHEMA_H_
 
-#include "config.h"
 #include "log.h"
 #include "parser_schema.h"
+#include "tests/config.h"
 
 /* set to 0 to printing error messages to stderr instead of checking them in code */
 #define ENABLE_LOGGER_CHECKING 1
diff --git a/tests/utests/schema/test_tree_schema_compile.c b/tests/utests/schema/test_tree_schema_compile.c
index ea6166e..85dcf0e 100644
--- a/tests/utests/schema/test_tree_schema_compile.c
+++ b/tests/utests/schema/test_tree_schema_compile.c
@@ -20,11 +20,11 @@
 #include <stdio.h>
 #include <string.h>
 
-#include "../../../src/common.h"
-#include "../../../src/tree_schema_internal.h"
-#include "../../../src/parser_internal.h"
-#include "../../../src/xpath.h"
-#include "../../../src/plugins_types.h"
+#include "common.h"
+#include "parser_internal.h"
+#include "plugins_types.h"
+#include "tree_schema_internal.h"
+#include "xpath.h"
 
 void lysc_feature_free(struct ly_ctx *ctx, struct lysc_feature *feat);
 void yang_parser_ctx_free(struct lys_yang_parser_ctx *ctx);