die_with_status: use "printf '%s\n'", not "echo"

Some implementations of 'echo' (e.g. dash's built-in) interpret
backslash sequences in their arguments.

This triggered at least one bug: the error message of "rebase -i" was
turning \t in commit messages into actual tabulations. There may be
others.

Using "printf '%s\n'" instead avoids this bad behavior, and is the form
used by the "say" function.

Noticed-by: David Kastrup <dak@gnu.org>
Signed-off-by: Matthieu Moy <Matthieu.Moy@imag.fr>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

git-sh-setup.sh

@@ -53,7 +53,7 @@ die () {
 die_with_status () {
 	status=$1
 	shift
-	echo >&2 "$*"
+	printf >&2 '%s\n' "$*"
 	exit "$status"
 }