itest: add error detection explanation

lntest/itest/log_check_errors.sh

@@ -2,6 +2,8 @@
 
 BASEDIR=$(dirname "$0")
 
+echo ""
+
 # Filter all log files for errors, substitute variable data and match against whitelist.
 cat $BASEDIR/*.log | grep "\[ERR\]" | \
 sed -r -f $BASEDIR/log_substitutions.txt | \
@@ -9,4 +11,16 @@ sort | uniq | \
 grep -Fvi -f $BASEDIR/log_error_whitelist.txt
 
 # If something shows up (not on whitelist) exit with error code 1.
-test $? -eq 1
+if [[ $? -eq 0 ]]; then
+        echo ""
+        echo "In the itest logs, the log line (patterns) above were detected."
+        echo "[ERR] lines are generally reserved for internal errors."
+        echo "Resolve the issue by either changing the log level or adding an "
+        echo "exception to log_error_whitelist.txt"
+        echo ""
+
+        exit 1
+fi
+
+echo "No itest errors detected."
+echo ""