Revert "Update Haddock submodule"

This reverts commit 34d68d8e83676c5010e9bc5d4619f24879f222af
as it breaks the build:

  Configuring hsc2hs-0.67...
  Configuring ghc-cabal-0.1...
  Configuring parallel-3.2.0.6...
  Configuring hpc-bin-0.67...
  Configuring haddock-2.16.0...
  ghc-cabal: At least the following dependencies are missing:
  ghc >=7.9 && <7.11
  make[1]: *** [utils/haddock/dist/package-data.mk] Error 1
  make[1]: *** Waiting for unfinished jobs....
    GHC PKG libraries/parallel/dist-install/package-data.mk
  Reading package info from "libraries/parallel/dist-install/inplace-pkg-config" ... done.
  parallel-3.2.0.6: Warning: haddock-interfaces: /srv/builds/commits/rGHC/B3035-34d68d8e83676c5010e9bc5d4619f24879f222af/libraries/parallel/dist-install/doc/html/parallel/parallel.haddock doesn't exist or isn't a file
  parallel-3.2.0.6: cannot find any of ["Control/Seq.hi","Control/Seq.p_hi","Control/Seq.dyn_hi"] (ignoring)
  parallel-3.2.0.6: cannot find any of ["Control/Parallel.hi","Control/Parallel.p_hi","Control/Parallel.dyn_hi"] (ignoring)
  parallel-3.2.0.6: cannot find any of ["Control/Parallel/Strategies.hi","Control/Parallel/Strategies.p_hi","Control/Parallel/Strategies.dyn_hi"] (ignoring)
  parallel-3.2.0.6: cannot find any of ["libHSparal_791B1zx5CJ25cUOFECtmw0.a","libHSparal_791B1zx5CJ25cUOFECtmw0.p_a","libHSparal_791B1zx5CJ25cUOFECtmw0-ghc7.11.20150123.so","libHSparal_791B1zx5CJ25cUOFECtmw0-ghc7.11.20150123.dylib","HSparal_791B1zx5CJ25cUOFECtmw0-ghc7.11.20150123.dll"] on library path (ignoring)
  make: *** [all] Error 2

Moreover, utils/haddock is supposed to track the `ghc-head` branch
(which is what `git submodule update --remote utils/haddock` helps with)

1 files changed, 0 insertions, 0 deletions

diff --git a/utils/haddock b/utils/haddock
-Subproject bf77580eb40fa960b701296ac828372d127a43d
+Subproject d61bbc75890e4eb0ad508b9c2a27b91f691213e