dtc: Flexible tree checking infrastructure (v2)

[Jon Loeliger]

So, like, the other day David Gibson mumbled:
> dtc: Flexible tree checking infrastructure
> 
> Here, at last, is a substantial start on revising dtc's infrastructure
> for checking the tree; this is the rework I've been saying was
> necessary practically since dtc was first release.
> 
> In the new model, we have a table of "check" structures, each with a
> name, references to checking functions, and status variables.  Each
> check can (in principle) be individually switched off or on (as either
> a warning or error).  Checks have a list of prerequisites, so if
> checks need to rely on results from earlier checks to make sense (or
> even to avoid crashing) they just need to list the relevant other
> checks there.
> 
> For now, only the "structural" checks and the fixups for phandle
> references are converted to the new mechanism.  The rather more
> involved semantic checks (which is where this new mechanism will
> really be useful) will have to be converted in future patches.
> 
> At present, there's no user interface for turning on/off the checks -
> the -f option now forces output even if "error" level checks fail.
> Again, future patches will be needed to add the fine-grained control,
> but that should be quite straightforward with the infrastructure
> implemented here.
> 
> Also adds a testcase for the handling of bad references, which catches
> a bug encountered while developing this patch.
> 
> Signed-off-by: David Gibson <david at gibson.dropbear.id.au>

While I've Applied this one, it has introduced this:

         CC dtc.o
    dtc.c: In function 'main':
    dtc.c:199: warning: 'structure_ok' is used uninitialized in this function

Followup easy patch?

Thanks,
jdl