tests CHANGE wrapping functions on OSX

OSX's linker does not support --wrap option to wrap a function. We use
it for testing, so disable such tests on OSX.
diff --git a/tests/CMakeLists.txt b/tests/CMakeLists.txt
index 68761ac..e8e1395 100644
--- a/tests/CMakeLists.txt
+++ b/tests/CMakeLists.txt
@@ -27,9 +27,11 @@
 # Set common attributes of all tests
 foreach(test_name IN LISTS tests)
     target_link_libraries(${test_name} ${CMOCKA_LIBRARIES} ${CMAKE_THREAD_LIBS_INIT} ${PCRE_LIBRARIES} m)
-    list(GET tests_wraps 0 test_wrap)
-    set_target_properties(${test_name} PROPERTIES LINK_FLAGS "${test_wrap}")
-    list(REMOVE_AT tests_wraps 0)
+    if (NOT APPLE)
+        list(GET tests_wraps 0 test_wrap)
+        set_target_properties(${test_name} PROPERTIES LINK_FLAGS "${test_wrap}")
+        list(REMOVE_AT tests_wraps 0)
+    endif()
     add_test(NAME ${test_name} COMMAND ${test_name})
 #    set_property(TEST ${test_name} PROPERTY ENVIRONMENT "LIBYANG_EXTENSIONS_PLUGINS_DIR=${CMAKE_BINARY_DIR}/src/extensions")
 #    set_property(TEST ${test_name} APPEND PROPERTY ENVIRONMENT "LIBYANG_USER_TYPES_PLUGINS_DIR=${CMAKE_BINARY_DIR}/src/user_types")