This patch removes the modification to CMakeLists.txt made to fake the presence of SystemD and OpenRC, since it doesn't provide any actual utility for Guix, and places thinkfan.pid in a non-default place: /run/thinkfan.pid. This patch corrects it, placing the pid file in /var/run/, like wpa_supplicant, dhclient, syslog, tor, thermald and other Guix Services.