Test: remove testdir also if skip test

test/test_snmp_system.sh

@@ -9,6 +9,7 @@ APPNAME=example
 
 if [ ${ENABLE_NETSNMP} != "yes" ]; then
     echo "Skipping test, Net-SNMP support not enabled."
+    rm -rf $dir
     if [ "$s" = $0 ]; then exit 0; else return 0; fi
 fi
 
@@ -235,5 +236,7 @@ expectpart "$($snmpwalkstr system)" 0 "SNMPv2-MIB::sysDescr = STRING: System des
 new "Cleaning up"
 testexit
 
+rm -rf $dir
+
 new "endtest"
 endtest