schema BUGFIX processing extension instance argument

Due to differences in YANG and YIN, the extension instance's argument is
processed differently. So far, the argument was missing when the source
format was YIN and extension was not compiled. This was breaking
printers and limiting even other use cases of the argument.

This patch solves the problem by getting the extension definition when
needed and finishing the argument processing not finished by YIN parser.
diff --git a/tests/utests/utests.h b/tests/utests/utests.h
index b57df7b..1ed4fb4 100644
--- a/tests/utests/utests.h
+++ b/tests/utests/utests.h
@@ -427,16 +427,14 @@
  * @param[in] NODE      pointer to lysp_ext_instance variable
  * @param[in] ARGUMENT  expected optional value of the extension's argument
  * @param[in] CHILD     0 -> node doesnt have child, 1 -> node have children
- * @param[in] COMPILED  0 -> compiled data dosnt exists, 1 -> compiled data exists
  * @param[in] PARENT_STMT expected value identifying placement of the extension instance
  * @param[in] PARENT_STMT_INDEX expected indentifi index
  * @param[in] FORMAT    expected format
  */
-#define CHECK_LYSP_EXT_INSTANCE(NODE, ARGUMENT, CHILD, COMPILED, PARENT_STMT, PARENT_STMT_INDEX, NAME, FORMAT) \
+#define CHECK_LYSP_EXT_INSTANCE(NODE, ARGUMENT, CHILD, PARENT_STMT, PARENT_STMT_INDEX, NAME, FORMAT) \
     assert_non_null(NODE); \
     CHECK_STRING((NODE)->argument, ARGUMENT); \
     CHECK_POINTER((NODE)->child, CHILD); \
-    CHECK_POINTER((NODE)->compiled, COMPILED); \
     /*assert_int_equal((NODE)->flags, LYS_INTERNAL);*/ \
     assert_int_equal((NODE)->parent_stmt, PARENT_STMT); \
     assert_int_equal((NODE)->parent_stmt_index, PARENT_STMT_INDEX); \