dmaengine: sh: usb-dmac: Use [] to denote a flexible array member

Flexible array members should be denoted using [] instead of [0], else
gcc will not warn when they are no longer at the end of the structure.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Simon Horman <horms+renesas@verge.net.au>
Signed-off-by: Vinod Koul <vkoul@kernel.org>

drivers/dma/sh/usb-dmac.c

@@ -57,7 +57,7 @@ struct usb_dmac_desc {
 	u32 residue;
 	struct list_head node;
 	dma_cookie_t done_cookie;
-	struct usb_dmac_sg sg[0];
+	struct usb_dmac_sg sg[];
 };
 
 #define to_usb_dmac_desc(vd)	container_of(vd, struct usb_dmac_desc, vd)