'echo -n' is not portable

[[Imported from SVN: r5121]]

m4/dune.m4

@@ -212,7 +212,7 @@ AC_DEFUN([DUNE_CHECK_MODULES],[
   # add this module to DUNE_SUMMARY
   txt=_dune_name
   indentlen=17
-  while test `echo -n $txt | wc -c` -lt $indentlen; do txt=$txt.; done
+  while test `echo $txt | tr -d '\n' | wc -c` -lt $indentlen; do txt=$txt.; done
   txt="$txt: $with_[]_dune_module"
   if test "x$_DUNE_MODULE[]_ROOT" != "x"; then
 	txt="$txt ($_DUNE_MODULE[]_ROOT)"