state: remove checks for xzalloc() returning NULL ...

This ports the following barebox commit:

| commit 25e67cb
| Author: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
| Date:   Mon Sep 25 12:02:35 2017 +0200
|
|     remove checks for xzalloc() returning NULL
|
|     xzalloc() either returns memory or panics, so checking for NULL is useless.
|
|     Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
|     Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

Signed-off-by: Ulrich Ölmann <u.oelmann@pengutronix.de>
Signed-off-by: Roland Hieber <rhi@pengutronix.de>

state: Fix "pack" returning freed data for DTB backend ...

This ports the following barebox commit:

| commit ec01cbc
| Author: Ian Abbott <abbotti@mev.co.uk>
| Date:   Fri Apr 21 10:53:25 2017 +0100
|
|     state: Fix "pack" returning freed data for DTB backend
|
|     `state_backend_format_dtb_pack()` passes a buffer containing state
|     packed in flattened DTB format back to its caller via its `buf`
|     parameter.  It then frees the buffer before returning.  This means the
|     caller (`state_save()`) will be working on freed buffer contents before
|     freeing the buffer a second time itself.  Fix it by removing the
|     spurious call to `free()`.
|
|     This should fix a bug reported by Norbert Wiedmann in
|     <http://lists.infradead.org/pipermail/barebox/2017-April/029980.html>.
|
|     Cc: Norbert Wiedmann <info@n-wiedmann.de>
|     Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
|     Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

Signed-off-by: Ulrich Ölmann <u.oelmann@pengutronix.de>
Signed-off-by: Roland Hieber <rhi@pengutronix.de>

Fix compiler warnings about wrong type conversion in messages. ...

These warning were observed with gcc-6.3 on x86-64.

Signed-off-by: Philipp Rosenberger <p.rosenberger@linutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

state: Allow to load without authentification ...

Sometimes it's useful to be able to load a state even when it
can't be authentificated. Add an option for this.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

state: Convert all bufs to void * ...

A void * is a much better type for a buffer than a u8 * as it
can be casted to any other type implicitly. Convert all buffers
used by the state framework to void *.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

state: replace len_hint logic ...

The len_hint mechanism is rather hard to understand as it's not clear
from where to where the hint is passed and also it's not clear what
happens if the hint is empty or wrong.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

barebox-state: Import updated state code ...

Signed-off-by: Markus Pargmann <mpa@pengutronix.de>