Fix or disable pylint warnings for inconsistent return.

In some places, disabling the warnings rather than fixing it required
less changes, without compromising readability.

plugins/modules/ipagroup.py

@@ -201,8 +201,8 @@ def find_group(module, name):
             msg="There is more than one group '%s'" % (name))
     elif len(_result["result"]) == 1:
         return _result["result"][0]
-    else:
-        return None
+
+    return None
 
 
 def gen_args(description, gid, nomembers):