fixed warning

lib/ansible/plugins/action/__init__.py

@@ -273,13 +273,8 @@ class ActionBase:
             else:
                 return data2.split()[0]
         except IndexError:
-            # FIXME: this should probably not print to sys.stderr, but should instead
-            #        fail in a more normal way?
-            sys.stderr.write("warning: Calculating checksum failed unusually, please report this to the list so it can be fixed\n")
-            sys.stderr.write("command: %s\n" % cmd)
-            sys.stderr.write("----\n")
-            sys.stderr.write("output: %s\n" % data)
-            sys.stderr.write("----\n")
+            self._display.warning("Calculating checksum failed unusually, please report this to " + \
+                "the list so it can be fixed\ncommand: %s\n----\noutput: %s\n----\n") % (cmd, data)
             # this will signal that it changed and allow things to keep going
             return "INVALIDCHECKSUM"