ATDM: Fix for non-hostname match systems (ATDV-228, trilinos#6276)

There was bad logic put in to fix the last bug.  This break the EMPIRE
Trilinos testing/integration process (trilinos#6276).

This script really needs to be put under automated test (see trilinos#5939).

cmake/std/atdm/utils/get_known_system_info.sh

@@ -114,8 +114,10 @@ fi
 
 #echo "hostnameMatch ='${hostnameMatch}'"
 
-systemNameTypeMatchedList+=(${hostnameMatchSystemName})
-systemNameTypeMatchedListHostNames[${hostnameMatchSystemName}]=${hostnameMatch}
+if [[ "${hostnameMatch}" != "" ]] ; then
+  systemNameTypeMatchedList+=(${hostnameMatchSystemName})
+  systemNameTypeMatchedListHostNames[${hostnameMatchSystemName}]=${hostnameMatch}
+fi
 
 #
 # C) Look for known system types that matches this machine