For the skipped ARC4 test, don't bother trying to run the test clean-up

code.  It runs rump.halt which returns an error status (since rump was
never started in the first place), and this causes atf to complain about
the cleanup routine's return status, logging the test as a failure!

tests/crypto/opencrypto/t_opencrypto.sh

@@ -1,4 +1,4 @@
-#	$NetBSD: t_opencrypto.sh,v 1.5 2015/03/16 16:42:27 prlw1 Exp $
+#	$NetBSD: t_opencrypto.sh,v 1.6 2015/12/26 07:10:03 pgoyette Exp $
 #
 # Copyright (c) 2014 The NetBSD Foundation, Inc.
 # All rights reserved.
@@ -80,7 +80,11 @@ arc4_body() {
 }
 
 arc4_cleanup() {
-	common_cleanup
+	# No cleanup required since test is skipped.  Trying to run rump.halt
+	# at this point fails, causing the ATF environment to erroneously
+	# report a failed test!
+	#
+	# common_cleanup
 }
 
 atf_test_case camellia cleanup