Only perform test cleanups in clean.sh scripts

Temporary files created by a given system test should be removed by its
clean.sh script, not its setup.sh script.  Remove redundant "rm"
invocations from setup.sh scripts.  Move required "rm" invocations from
setup.sh scripts to their corresponding clean.sh scripts.

bin/tests/system/nsupdate/setup.sh

@@ -12,7 +12,11 @@
 SYSTEMTESTTOP=..
 . $SYSTEMTESTTOP/conf.sh
 
+#
+# jnl and database files MUST be removed before we start
+#
 $SHELL clean.sh
+
 copy_setports ns1/named.conf.in ns1/named.conf
 copy_setports ns2/named.conf.in ns2/named.conf
 copy_setports ns3/named.conf.in ns3/named.conf
@@ -25,15 +29,6 @@ copy_setports ns10/named.conf.in ns10/named.conf
 
 copy_setports verylarge.in verylarge
 
-#
-# jnl and database files MUST be removed before we start
-#
-
-rm -f ns1/*.jnl ns1/example.db ns2/*.jnl ns2/example.bk
-rm -f ns2/update.bk ns2/update.alt.bk
-rm -f ns3/example.db.jnl
-rm -f ns3/too-big.test.db.jnl
-
 cp -f ns1/example1.db ns1/example.db
 sed 's/example.nil/other.nil/g' ns1/example1.db > ns1/other.db
 sed 's/example.nil/unixtime.nil/g' ns1/example1.db > ns1/unixtime.db
@@ -71,13 +66,11 @@ $DDNSCONFGEN -q -a hmac-sha512 -k sha512-key -z keytests.nil > ns1/sha512.key
 (cd ns3; $SHELL -e sign.sh)
 
 cp -f ns1/many.test.db.in ns1/many.test.db
-rm -f ns1/many.test.db.jnl
 
 cp ns1/sample.db.in ns1/sample.db
 cp ns2/sample.db.in ns2/sample.db
 
 cp -f ns1/maxjournal.db.in ns1/maxjournal.db
-rm -f ns1/maxjournal.db.jnl
 
 cp -f ns5/local.db.in ns5/local.db
 cp -f ns6/in-addr.db.in ns6/in-addr.db