selftests: fib_rule_tests: use pre-defined DEV_ADDR

DEV_ADDR is defined but not used. Use it in address setting.
Do the same with IPv6 for consistency.
Reported-by: David Ahern <dsahern@gmail.com>
Fixes: fc82d93e ("selftests: fib_rule_tests: fix local IPv4 address typo")
Signed-off-by: Hangbin Liu <liuhangbin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

tools/testing/selftests/net/fib_rule_tests.sh

@@ -15,6 +15,7 @@ GW_IP6=2001:db8:1::2
 SRC_IP6=2001:db8:1::3
 
 DEV_ADDR=192.51.100.1
+DEV_ADDR6=2001:db8:1::1
 DEV=dummy0
 
 log_test()
@@ -55,8 +56,8 @@ setup()
 
 	$IP link add dummy0 type dummy
 	$IP link set dev dummy0 up
-	$IP address add 192.51.100.1/24 dev dummy0
-	$IP -6 address add 2001:db8:1::1/64 dev dummy0
+	$IP address add $DEV_ADDR/24 dev dummy0
+	$IP -6 address add $DEV_ADDR6/64 dev dummy0
 
 	set +e
 }