dmaengine: mv_xor: remove write-only is_complete_cookie

mv_xor's is_complete_cookie is only ever written to, but never read.
This is silly, remove the write-only structure member.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Tested-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Jassi Brar <jassisinghbrar@gmail.com>
[imx-sdma.c & mxs-dma.c]
Tested-by: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Vinod Koul <vinod.koul@linux.intel.com>

drivers/dma/mv_xor.c

@@ -826,7 +826,6 @@ static enum dma_status mv_xor_status(struct dma_chan *chan,
 
 	last_used = chan->cookie;
 	last_complete = mv_chan->completed_cookie;
-	mv_chan->is_complete_cookie = cookie;
 	dma_set_tx_state(txstate, last_complete, last_used, 0);
 
 	ret = dma_async_is_complete(cookie, last_complete, last_used);

drivers/dma/mv_xor.h

@@ -109,7 +109,6 @@ struct mv_xor_chan {
 #ifdef USE_TIMER
 	unsigned long		cleanup_time;
 	u32			current_on_last_cleanup;
-	dma_cookie_t		is_complete_cookie;
 #endif
 };