Move our minimum Sphinx version to 1.7

As promised, drop support for some ancient sphinx releases, along with a
lot of the cruft that was required to make that support work.

Signed-off-by: Jonathan Corbet <corbet@lwn.net>
diff --git a/Documentation/sphinx/kerneldoc.py b/Documentation/sphinx/kerneldoc.py
index e9857ab..8189c33 100644
--- a/Documentation/sphinx/kerneldoc.py
+++ b/Documentation/sphinx/kerneldoc.py
@@ -37,18 +37,8 @@
 from docutils import nodes, statemachine
 from docutils.statemachine import ViewList
 from docutils.parsers.rst import directives, Directive
-
-#
-# AutodocReporter is only good up to Sphinx 1.7
-#
 import sphinx
-
-Use_SSI = sphinx.__version__[:3] >= '1.7'
-if Use_SSI:
-    from sphinx.util.docutils import switch_source_input
-else:
-    from sphinx.ext.autodoc import AutodocReporter
-
+from sphinx.util.docutils import switch_source_input
 import kernellog
 
 __version__  = '1.0'
@@ -163,18 +153,8 @@
             return [nodes.error(None, nodes.paragraph(text = "kernel-doc missing"))]
 
     def do_parse(self, result, node):
-        if Use_SSI:
-            with switch_source_input(self.state, result):
-                self.state.nested_parse(result, 0, node, match_titles=1)
-        else:
-            save = self.state.memo.title_styles, self.state.memo.section_level, self.state.memo.reporter
-            self.state.memo.reporter = AutodocReporter(result, self.state.memo.reporter)
-            self.state.memo.title_styles, self.state.memo.section_level = [], 0
-            try:
-                self.state.nested_parse(result, 0, node, match_titles=1)
-            finally:
-                self.state.memo.title_styles, self.state.memo.section_level, self.state.memo.reporter = save
-
+        with switch_source_input(self.state, result):
+            self.state.nested_parse(result, 0, node, match_titles=1)
 
 def setup(app):
     app.add_config_value('kerneldoc_bin', None, 'env')