sphinx: conf.py: properly handle Sphinx 4.0

One of the checks for Sphinx 3+ is broken, causing some
C warnings to return back with Sphinx 4.0.x.
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Link: https://lore.kernel.org/r/d5abc30056dafeec0778a46263a45401bdc7f11e.1603791716.git.mchehab+huawei@kernel.orgSigned-off-by: Jonathan Corbet <corbet@lwn.net>

Documentation/conf.py

@@ -50,7 +50,7 @@ if major >= 3:
         support for Sphinx v3.0 and above is brand new. Be prepared for
         possible issues in the generated output.
         ''')
-    if minor > 0 or patch >= 2:
+    if (major > 3) or (minor > 0 or patch >= 2):
         # Sphinx c function parser is more pedantic with regards to type
         # checking. Due to that, having macros at c:function cause problems.
         # Those needed to be scaped by using c_id_attributes[] array