Tweak to avoid pylint warning.

src/gevent/resolver/dnspython.py

@@ -18,16 +18,18 @@ __all__ = [
 
 # Import the DNS packages to use the gevent modules,
 # even if the system is not monkey-patched.
-dns = import_patched('dns')
-
-for pkg in ('dns',
+def _patch_dns():
+    top = import_patched('dns')
+    for pkg in ('dns',
                 'dns.rdtypes',
                 'dns.rdtypes.IN',
                 'dns.rdtypes.ANY'):
         mod = import_patched(pkg)
         for name in mod.__all__:
             setattr(mod, name, import_patched(pkg + '.' + name))
+    return top
 
+dns = _patch_dns()
 
 def _dns_import_patched(name):
     assert name.startswith('dns')