[gtk-doc] Run vulture and apply some fixes.

[Stefan Sauer <stefkost src gnome org>]

commit 846d4c76c741c6fa6c91f1d92f5b98fc6662aead
Author: Stefan Sauer <ensonic users sf net>
Date:   Tue Dec 18 19:52:18 2018 +0100

    Run vulture and apply some fixes.
    
    Remove an unused import and fix a copy'n'paste in variable use.

 HACKING           | 5 +++++
 gtkdoc/mkhtml2.py | 1 -
 gtkdoc/scan.py    | 2 +-
 3 files changed, 6 insertions(+), 2 deletions(-)
---
diff --git a/HACKING b/HACKING
index f4b007b..63b7d65 100644
--- a/HACKING
+++ b/HACKING
@@ -120,3 +120,8 @@ python3-coverage html --include="gtkdoc/*.py"
 or
 
 cd test; make coverage
+
+Find Dead Code
+==============
+sudo pip3 install vulture
+PYTHONPATH=$PWD vulture gtkdoc/*.py gtkdoc-*.in
\ No newline at end of file
diff --git a/gtkdoc/mkhtml2.py b/gtkdoc/mkhtml2.py
index 06d8001..1a776e1 100644
--- a/gtkdoc/mkhtml2.py
+++ b/gtkdoc/mkhtml2.py
@@ -97,7 +97,6 @@ rm html-build.stamp; time make html-build.stamp
 """
 
 import argparse
-import errno
 import logging
 import os
 import shutil
diff --git a/gtkdoc/scan.py b/gtkdoc/scan.py
index dc1f140..cf277f8 100644
--- a/gtkdoc/scan.py
+++ b/gtkdoc/scan.py
@@ -123,7 +123,7 @@ CLINE_MATCHER = [
         (?:\s+\*+|\*+|\s)\s*
         (?:const\s+)*
         ([A-Za-z]\w*)                        # 1: name
-        \s*\=""" % RET_TYPE_MODIFIER, re.VERBOSE),
+        \s*\=""" % VAR_TYPE_MODIFIER, re.VERBOSE),
     # 17: G_DECLARE_*
     re.compile(
         r""".*G_DECLARE_