Make documentation for byteSwap16 consistent with byteSwap32 (impl is same, with s/16/32)
Make documentation for byteSwap16 consistent with byteSwap32 (impl is same, with s/16/32)

sdiehl/ghc,sdiehl/ghc,sdiehl/ghc,sdiehl/ghc,sdiehl/ghc,sdiehl/ghc,sdiehl/ghc