onDocFormSave examples use `$modx->log` inconsistently

[gingerchew]

Affected page(s)

https://docs.modx.com/current/en/extending-modx/plugins/system-events/ondocformsave

What needs to be improved?

In the first and third examples, the logging is written like this: $modx->log(MODX_LOG_LEVEL_ERROR, ...) and then in the second and fourth code block it is $modx->log(modX::LOG_LEVEL_ERROR, ...).