[PATCH] NVMe: fix uninitialized iod compiler warning

[Matthew Wilcox]

On Wed, Jul 25, 2012 at 04:04:29PM -0600, Keith Busch wrote:
>  	int status, length;
> -	struct nvme_iod *iod;
> +	struct nvme_iod *iod = NULL;
>  

So this is a compiler bug.  And it's not present in every compiler
version; it didn't occur on my machine until I upgraded gcc recently.
There's no way that iod can be used uninitialised.  The correct way to
indicate this is:

+	struct nvme_iod *uninitialized_var(iod);