Revert an erroneous change from r138874.

http/tests/misc/link-rel-icon-beforeload.html had been skipped prior to r138874
and it should continued to be.

* platform/mac-wk2/TestExpectations:


git-svn-id: http://svn.webkit.org/repository/webkit/trunk@138911 268f45cc-cd09-0410-ab3c-d52691b4dbfc