coverity#1433647 Unchecked return value from library

Change-Id: I05c91dc21ddcef0f64f712f4fe9a5736b0cee0f9
Reviewed-on: https://gerrit.libreoffice.org/52059Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Caolán McNamara <caolanm@redhat.com>
Tested-by: Caolán McNamara <caolanm@redhat.com>

sfx2/qa/cppunit/test_misc.cxx

@@ -171,7 +171,8 @@ void MiscTest::testHardLinks()
     xStorable->store();
 
     struct stat buf;
-    stat(aOld.getStr(), &buf);
+    int nRet = stat(aOld.getStr(), &buf);
+    CPPUNIT_ASSERT_EQUAL(nRet, 0);
     // This failed: hard link count was 1, the hard link broke on store.
     CPPUNIT_ASSERT(buf.st_nlink > 1);