dmaengine: ioatdma: fix u16 overflow in cleanup

If the allocation order is 16, then the u16 count will overflow and wrap
to zero when assigned the value 1 << 16.

Change the type of 'total_descs' to int, so that it is large enough to
store a value equal or greater than 1 << 16.
Signed-off-by: Allen Hubbe <Allen.Hubbe@emc.com>
Acked-by: Dave Jiang <dave.jiang@intel.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

drivers/dma/ioat/dma_v2.c

@@ -798,7 +798,7 @@ void ioat2_free_chan_resources(struct dma_chan *c)
 	struct ioat_chan_common *chan = &ioat->base;
 	struct ioatdma_device *device = chan->device;
 	struct ioat_ring_ent *desc;
-	const u16 total_descs = 1 << ioat->alloc_order;
+	const int total_descs = 1 << ioat->alloc_order;
 	int descs;
 	int i;