Update log and warning logger functions comment according to the actual functionality

[matiasbenedetto]

What?

Update log and warning logger functions comment according to the actual functionality.

In this PR I'm updating those 2 function comments to state that as the other logging function being muted by the --quiet command. Example:

wp-cli/php/class-wp-cli.php

Line 773 in 0a48e09

* Success message is written to STDOUT, or discarded when `--quiet` flag is supplied.

Why?

Both functions log nothing when running wp-cli with --quiet option.

Reference:

wp-cli/php/WP_CLI/Loggers/Quiet.php

Lines 37 to 44 in 0a48e09

	/**
	* Warning messages aren't logged.
	*
	* @param string $message Message to write.
	*/
	public function warning( $message ) {
	// Nothing.
	}