Remove symlinks time comparison tests from wxFileName test

These tests don't seem to be sound, it's possible for one second or more to
pass between the two calls to GetTimes() and it's apparently possible for the
access time on the symlink to not change (due to /tmp being mounted with
"noatime" option perhaps?), resulting in Travis CI build failures.

tests/filename/filenametest.cpp

@@ -827,9 +827,6 @@ void FileNameTestCase::TestSymlinks()
 
     wxFileName tmpfn(wxFileName::DirName(tmpdir));
 
-    wxDateTime dtAccessTmp, dtModTmp, dtCreateTmp;
-    CPPUNIT_ASSERT(tmpfn.GetTimes(&dtAccessTmp, &dtModTmp, &dtCreateTmp));
-
     // Create a temporary directory
 #ifdef __VMS
     wxString name = tmpdir + ".filenametestXXXXXX]";
@@ -917,18 +914,6 @@ void FileNameTestCase::TestSymlinks()
             linktodir.GetTimes(&dtAccess, &dtMod, &dtCreate)
         );
 
-        // IsEqualTo() should be true only when dereferencing. Don't test each
-        // individually: accessing to create the link will have updated some
-        bool equal = dtCreate.IsEqualTo(dtCreateTmp) &&
-                     dtMod.IsEqualTo(dtModTmp) &&
-                     dtAccess.IsEqualTo(dtAccessTmp);
-        CPPUNIT_ASSERT_EQUAL_MESSAGE
-        (
-            "Comparing directory times" + msg,
-            deref,
-            equal
-        );
-
         // Test (File|Dir)Exists()
         CPPUNIT_ASSERT_EQUAL_MESSAGE
         (