Use sphinx.version_info directly instead of parsing

Using the development version of sphinx caused the parsing of the
version to fail.

Signed-off-by: Rémy Léone <remy.leone@gmail.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
diff --git a/Documentation/conf.py b/Documentation/conf.py
index f2b9161..08aef45 100644
--- a/Documentation/conf.py
+++ b/Documentation/conf.py
@@ -17,7 +17,7 @@
 import sphinx
 
 # Get Sphinx version
-major, minor, patch = map(int, sphinx.__version__.split("."))
+major, minor, patch = sphinx.version_info[:3]
 
 
 # If extensions (or modules to document with autodoc) are in another directory,
@@ -29,7 +29,7 @@
 # -- General configuration ------------------------------------------------
 
 # If your documentation needs a minimal Sphinx version, state it here.
-#needs_sphinx = '1.0'
+needs_sphinx = '1.2'
 
 # Add any Sphinx extension module names here, as strings. They can be
 # extensions coming with Sphinx (named 'sphinx.ext.*') or your custom