block: rnbd-clt: Fix signedness bug in init_dev()

The "dev->clt_device_id" variable is set using ida_alloc_max() which
returns an int and in particular it returns negative error codes.
Change the type from u32 to int to fix the error checking.

Fixes: c9b5645fd8 ("block: rnbd-clt: Fix leaked ID in init_dev()")
Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

drivers/block/rnbd/rnbd-clt.h

@@ -112,7 +112,7 @@ struct rnbd_clt_dev {
 	struct rnbd_queue	*hw_queues;
 	u32			device_id;
 	/* local Idr index - used to track minor number allocations. */
-	u32			clt_device_id;
+	int			clt_device_id;
 	struct mutex		lock;
 	enum rnbd_clt_dev_state	dev_state;
 	refcount_t		refcount;