echo -n isn't supported by all shells, use printf instead, which is portable.

Patch by Andrew Miller.

https://bugs.gentoo.org/529992

--- a/configure
+++ b/configure
@@ -235,10 +235,7 @@
 
 echo 'Generating MCONFIG...'
 (
-    echo -n '# Generated by configure (confgen version 2) on '
-    date
-    echo '#'
-    echo
+    printf "#\n# Generated by configure (confgen version 2) on $(date)\n#\n\n"
 
     echo "SBINDIR=$SBINDIR"
     echo "MANDIR=$MANDIR"