network scripts need sysfs on linux systems

Adjust the previous commit so that on linux systems the network scripts
need sysfs.

init.d/net.lo.in

@@ -19,6 +19,9 @@ depend()
 	local IFVAR=$(shell_var "${IFACE}")
 
 	need localmount
+	if [ "$RC_UNAME" = Linux ]; then
+		need sysfs
+	fi
 	after bootmisc
 	keyword -jail -vserver
 

net/ifconfig.sh.Linux.in

@@ -5,9 +5,6 @@ ifconfig_depend()
 {
 	program /sbin/ifconfig /bin/ifconfig
 	provide interface
-	case "${IFACE}" in
-		lo|lo0) need sysfs ;;
-	esac
 }
 
 _up()

net/iproute2.sh

@@ -6,9 +6,6 @@ iproute2_depend()
 	program ip
 	provide interface
 	after ifconfig
-	case "${IFACE}" in
-		lo|lo0) need sysfs ;;
-	esac
 }
 
 _up()