rc: virtual_oss: Use required_modules instead of load_kld

Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
Reviewed by:	imp, markj, emaste
Differential Revision:	https://reviews.freebsd.org/D53616

libexec/rc/rc.d/virtual_oss

@@ -20,6 +20,8 @@ start_cmd="${name}_start"
 stop_cmd="${name}_stop"
 status_cmd="${name}_status"
 
+required_modules="cuse"
+
 configs=
 pidpath="/var/run/${name}"
 virtual_oss_default_args="\
@@ -53,7 +55,6 @@ virtual_oss_pids()
 virtual_oss_precmd()
 {
 	/usr/bin/install -d -m 0755 -o root "${pidpath}"
-	load_kld cuse
 }
 
 start_instance()