per-config failure threshold acts unintuitively

[xd009642]

You can set a failure-threshold per config, however only the state of the last one is reported as an error. When creating this it was intended to be a global config on reporting or a single config file (so global config). However, for a specific configuration (i.e. feature set) a different threshold may be required. Make any failure-threshold failure on a config entry fail the run. Noticed in https://github.com/xd009642/tarpaulin/pull/993