Log: libpacemaker: Drop crm_perror() in pcmk_graph_consumer.c

The only thing we lose here is writing the message to stderr for CLI
tools. However, CLI tools have verbose options. It doesn't seem worth
passing pcmk__output_t down the call chain.

Other errors in this file already simply use crm_err(), etc.

Ref T172

Signed-off-by: Reid Wahl <nrwahl@protonmail.com>