* gnu/services/spice.scm (spice-vdagent-activation): Update runtime directory
from /var/run/spice-vdagentd to /run/spice-vdagentd.
(spice-vdagent-service-type): Specify a default value and fix indentation.
Passing 'make-forkexec-constructor' a string or several string arguments
has been deprecated since dmd 0.1.
* gnu/services/base.scm (rngd-service-type): In 'start' method, pass a
list as the first argument to 'make-forkexec-constructor'.
* gnu/services/desktop.scm (bluetooth-shepherd-service): Likewise.
* gnu/services/spice.scm (spice-vdagent-shepherd-service): Likewise.