Fix double MaybeT instance
Fix double MaybeT instance

This is a fixup to fd3b845c01aa26b6e5cd12c00af59e5468e21b1b
which didn't take into account 09333313f32be975faf9158fcd3648489d78ad82
having pushed as well.

shlevy/ghc,gridaphobe/ghc,nushio3/ghc,sgillespie/ghc,olsner/ghc,mcschroeder/ghc,vikraman/ghc,GaloisInc/halvm-ghc,ezyang/ghc,vTurbine/ghc,mcschroeder/ghc,tjakway/ghcjvm,gridaphobe/ghc,olsner/ghc,vikraman/ghc,vikraman/ghc,mcschroeder/ghc,sgillespie/ghc,nushio3/ghc,GaloisInc/halvm-ghc,tjakway/ghcjvm,sdiehl/ghc,sgillespie/ghc,mettekou/ghc,oldmanmike/ghc,snoyberg/ghc,snoyberg/ghc,sgillespie/ghc,shlevy/ghc,mcschroeder/ghc,GaloisInc/halvm-ghc,shlevy/ghc,gridaphobe/ghc,oldmanmike/ghc,GaloisInc/halvm-ghc,ezyang/ghc,sgillespie/ghc,mcschroeder/ghc,shlevy/ghc,vTurbine/ghc,tjakway/ghcjvm,tjakway/ghcjvm,olsner/ghc,mettekou/ghc,sdiehl/ghc,gridaphobe/ghc,snoyberg/ghc,nushio3/ghc,tjakway/ghcjvm,vikraman/ghc,sdiehl/ghc,GaloisInc/halvm-ghc,mcschroeder/ghc,nushio3/ghc,vikraman/ghc,mettekou/ghc,shlevy/ghc,shlevy/ghc,gridaphobe/ghc,oldmanmike/ghc,snoyberg/ghc,GaloisInc/halvm-ghc,gridaphobe/ghc,snoyberg/ghc,shlevy/ghc,sdiehl/ghc,vTurbine/ghc,oldmanmike/ghc,snoyberg/ghc,mcschroeder/ghc,ezyang/ghc,sdiehl/ghc,snoyberg/ghc,mettekou/ghc,sgillespie/ghc,olsner/ghc,vTurbine/ghc,olsner/ghc,nushio3/ghc,ezyang/ghc,oldmanmike/ghc,nushio3/ghc,oldmanmike/ghc,vikraman/ghc,vTurbine/ghc,tjakway/ghcjvm,olsner/ghc,vTurbine/ghc,mettekou/ghc,nushio3/ghc,vikraman/ghc,sdiehl/ghc,olsner/ghc,oldmanmike/ghc,sgillespie/ghc,ezyang/ghc,sdiehl/ghc,ezyang/ghc,mettekou/ghc,mettekou/ghc,ezyang/ghc,gridaphobe/ghc,tjakway/ghcjvm,GaloisInc/halvm-ghc,vTurbine/ghc