memoize self.state
memoize self.state

we memoize the output of check_running_state.

this also helps clarify the name of the function
self.check_running_state, which now no longer modifies a class-global
variable, and instead just returns the state

This pull Request is a Regression and is caused by #232 / #225 (which the author naïvely approved)

Fixes #240

crayfishx/puppet-firewalld,crayfishx/puppet-firewalld