ipq40xx: add missing case closing symbol

Though not strictly necessary, add the closing symbol to make the
job easier for future developers editing this file.

Signed-off-by: Adrian Schmutzler <freifunk@adrianschmutzler.de>

target/linux/ipq40xx/base-files/lib/preinit/05_set_iface_mac_ipq40xx.sh

@@ -29,6 +29,7 @@ preinit_set_mac_address() {
 		base_mac=$(cat /sys/class/net/eth0/address)
 		ip link set dev eth0 address $(macaddr_add "$base_mac" 2)
 		ip link set dev eth1 address $(macaddr_add "$base_mac" 3)
+		;;
 	esac
 }