schematestutils.sh: improve shell portability: avoid "echo -e"

* tests/schematestutils.sh: Use printf rather than echo -e.

tests/schematestutils.sh

@@ -22,7 +22,7 @@ do
 
     test_result $n $(basename $(dirname $xml))"/"$(basename $xml) $ret
     if test "$verbose" = "1" && test $ret != 0 ; then
-        echo -e "$cmd\n$result"
+        printf '%s\n' "$cmd" "$result"
     fi
     if test "$ret" != 0 ; then
         f=`expr $f + 1`