carbon.conf: Set PID_DIR=/var/run

Without this, when carbon cache is run from /usr/bin/carbon, it thinks
GRAPHITE_ROOT is /usr, and tries to create pidfiles by default under
/usr/storage

Signed-off-by: Tim Serong <tserong@suse.com>
calamari_ctl.py: Use `systemctl restart cthulhu` on SUSE

Signed-off-by: Tim Serong <tserong@suse.com>