[fix] Add missing append flags to tee

setup/so-setup

@@ -115,7 +115,7 @@ case "$setup_type" in
 		echo "Beginning Security Onion $setup_type install" >> $setup_log 2>&1
 		;;
 	*)
-		echo "Invalid install type, must be 'iso' or 'network'" | tee $setup_log
+		echo "Invalid install type, must be 'iso' or 'network'" | tee -a $setup_log
 		exit 1
 		;;
 esac
@@ -156,7 +156,7 @@ if ! [ -f /root/install_opt ]; then
 	if (whiptail_you_sure); then
 		true
 	else
-		echo "User cancelled setup." | tee "$setup_log"
+		echo "User cancelled setup." | tee -a "$setup_log"
 		whiptail_cancel
 	fi