Update tapview and tapdiffer.

tests/tapdiffer

@@ -1,6 +1,4 @@
 #! /bin/sh
-# SPDX-FileCopyrightText: Copyright Eric S. Raymond <esr@thyrsus.com>
-# SPDX-License-Identifier: MIT-0
 #
 # tapdiffer - Render diff between input and checkfile as a TAP report
 #
@@ -16,17 +14,23 @@
 # OSD-compliant; otherwise the following SPDX tag incorporates the
 # MIT No Attribution license by reference.
 #
+# SPDX-FileCopyrightText: (C) Eric S. Raymond <esr@thyrsus.com>
+# SPDX-License-Identifier: MIT-0
+#
 # A newer version may be available at https://gitlab.com/esr/tapview
 # Check your last commit dqte for this file against the commit list
 # there to see if it might be a good idea to update.
 #
-if [ "$1" = "-b" ]
-then
-    diffopts=-ub
-    shift
-else
-    diffopts=-u
-fi
+diffopts=-u
+while getopts bn opt
+do
+    case $opt in
+	b) diffopts=-ub;;
+	*) echo "tapdiffer: unknown option ${opt}."; exit 1;;
+    esac
+done
+# shellcheck disable=SC2004
+shift $(($OPTIND - 1))
 
 legend=$1
 checkfile=$2
@@ -37,7 +41,7 @@ if diff --text "${diffopts}" "${checkfile}" - >/tmp/tapdiff$$
 then
 	echo "ok - ${legend}"
 else
-	echo "not ok - ${checkfile}: ${legend}"
+	echo "not ok - ${legend}"
 	if [ ! "${QUIET}" = 1 ]
 	then
 		echo "  --- |"