rc: virtual_oss: Define some variables in rc.conf

They will now be part of /etc/defaults/rc.conf and be accessible by
sysrc(8).

Fixes:		70e27ecba5 ("virtual_oss: Introduce virtual_oss_default_control_device rc variable")
PR:		295560
Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
Reviewed by:	0mp, jrm
Pull-Reqeust:	https://ron-dev.freebsd.org/FreeBSD/src/pulls/33

libexec/rc/rc.conf

@@ -736,7 +736,11 @@ newsyslog_flags="-CN"	# Newsyslog flags to create marked files
 mixer_enable="YES"	# Run the sound mixer.
 opensm_enable="NO"	# Opensm(8) for infiniband devices defaults to off
 nuageinit_enable="NO"	# Run nuageinit at startup
-virtual_oss_enable="NO" # Run virtual_oss at startup
+
+virtual_oss_enable="NO"				# Run virtual_oss at startup.
+virtual_oss_configs="dsp"			# List of configurations.
+virtual_oss_default_control_device="vdsp.ctl"	# Default configuration's
+						# control device.
 
 # rctl(8) requires kernel options RACCT and RCTL
 rctl_enable="YES"		# Load rctl(8) rules on boot

libexec/rc/rc.d/virtual_oss

@@ -22,13 +22,9 @@ status_cmd="${name}_status"
 
 required_modules="cuse"
 
-configs=
 pidpath="/var/run/${name}"
+
 default_unit=$(sysctl -n hw.snd.default_unit 2> /dev/null)
-
-# Default configuration's control device.
-: "${virtual_oss_default_control_device:="vdsp.ctl"}"
-
 virtual_oss_default_args="\
 	-S \
 	-C 2 \
@@ -42,12 +38,6 @@ virtual_oss_default_args="\
 	-l dsp.loop \
 	-t ${virtual_oss_default_control_device}"
 
-# Set to NO by default. Set it to "YES" to enable virtual_oss.
-: "${virtual_oss_enable:="NO"}"
-
-#  List of configurations to use. Default is "dsp".
-: "${virtual_oss_configs:="dsp"}"
-
 # Default (dsp) virtual_oss config.
 : "${virtual_oss_dsp:="${virtual_oss_default_args}"}"