hush_test: update test output to match new getopt() output

Signed-off-by: Mike Frysinger <vapier@gentoo.org>
diff --git a/shell/hush_test/hush-vars/unset.right b/shell/hush_test/hush-vars/unset.right
index 1fbe76a..0da0e57 100644
--- a/shell/hush_test/hush-vars/unset.right
+++ b/shell/hush_test/hush-vars/unset.right
@@ -1,5 +1,5 @@
 0
-unset: invalid option -- m
+unset: invalid option -- 'm'
 1
 0
 ___