Unskip filter-fallback-to-software.html on Mac WK2 Release

Patch by Benjamin Poulain <bpoulain@apple.com> on 2013-04-02

* platform/mac-wk2/TestExpectations:
The test seems to pass in Release. Let's see how the bots feel about that.


git-svn-id: http://svn.webkit.org/repository/webkit/trunk@147515 268f45cc-cd09-0410-ab3c-d52691b4dbfc