selftests: Fix suppress test in fib_tests.sh

fib_tests is spewing errors:
    ...
    Cannot open network namespace "ns1": No such file or directory
    Cannot open network namespace "ns1": No such file or directory
    Cannot open network namespace "ns1": No such file or directory
    Cannot open network namespace "ns1": No such file or directory
    ping: connect: Network is unreachable
    Cannot open network namespace "ns1": No such file or directory
    Cannot open network namespace "ns1": No such file or directory
    ...

Each test entry in fib_tests is supposed to do its own setup and
cleanup. Right now the $IP commands in fib_suppress_test are
failing because there is no ns1. Add the setup/cleanup and logging
expected for each test.

Fixes: ca7a03c4 ("ipv6: do not free rt if FIB_LOOKUP_NOREF is set on suppress rule")
Signed-off-by: David Ahern <dsahern@gmail.com>
Cc: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

tools/testing/selftests/net/fib_tests.sh

@@ -618,16 +618,22 @@ fib_nexthop_test()
 
 fib_suppress_test()
 {
+	echo
+	echo "FIB rule with suppress_prefixlength"
+	setup
+
 	$IP link add dummy1 type dummy
 	$IP link set dummy1 up
 	$IP -6 route add default dev dummy1
 	$IP -6 rule add table main suppress_prefixlength 0
-	ping -f -c 1000 -W 1 1234::1 || true
+	ping -f -c 1000 -W 1 1234::1 >/dev/null 2>&1
 	$IP -6 rule del table main suppress_prefixlength 0
 	$IP link del dummy1
 
 	# If we got here without crashing, we're good.
-	return 0
+	log_test 0 0 "FIB rule suppress test"
+
+	cleanup
 }
 
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