Log: libcib: Drop crm_perror() in cib_file.c

Most errors in this file already use crm_err(), etc. It seems that
crm_perror() was used more as a convenience wrapper for logging
strerror(errno), rather than as a way to log to stderr.

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.

Ref T172

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