[gtk-doc] check: mark regex string as raw string

[Stefan Sauer <stefkost src gnome org>]

commit 0ead240f38eb038abe4e7c0c294c63629e7162cc
Author: Stefan Sauer <ensonic users sf net>
Date:   Sun Apr 16 15:39:44 2017 +0200

    check: mark regex string as raw string

 gtkdoc/check.py |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/gtkdoc/check.py b/gtkdoc/check.py
index 8552d89..a4e93d8 100755
--- a/gtkdoc/check.py
+++ b/gtkdoc/check.py
@@ -70,7 +70,7 @@ def check_includes(filename):
 
 def get_variable(env, lines, variable):
     value = env.get(variable,
-                    grep(r'^\s*' + variable + '\s*=\s*(\S+)', lines, variable))
+                    grep(r'^\s*' + variable + r'\s*=\s*(\S+)', lines, variable))
     return value