[3.x] Fix fatal error when using the `--suffix` argument
[3.x] Fix fatal error when using the `--suffix` argument

Running `phpcbf` with the `--sufffix` argument caused a fatal `array to string conversion` error.

jrfnl/PHP_CodeSniffer,fabacino/PHP_CodeSniffer,fabacino/PHP_CodeSniffer,arnested/PHP_CodeSniffer,stronk7/PHP_CodeSniffer,jrfnl/PHP_CodeSniffer,VANINUitgeverij/PHP_CodeSniffer,squizlabs/PHP_CodeSniffer,jrfnl/PHP_CodeSniffer,arnested/PHP_CodeSniffer,fabacino/PHP_CodeSniffer,VANINUitgeverij/PHP_CodeSniffer,squizlabs/PHP_CodeSniffer,VANINUitgeverij/PHP_CodeSniffer,arnested/PHP_CodeSniffer,stronk7/PHP_CodeSniffer,squizlabs/PHP_CodeSniffer,stronk7/PHP_CodeSniffer