[Xmonad] Patch: Operations.hs: deobfuscate Tall's doLayout and make use of fromMaybe

I wasn't intending to make a flood of small patches, I just noticed these things when looking to see how messy it would be for the default layouts to honor applyHints by default. -- Eric Mertens Phone: 503.626.6616, x155 Galois Fax: 503.214.8120 12725 SW Millikan Way Ste 290 http://www.galois.com Beaverton, OR 97005-1691 emertens@galois.com