crypto: dcp - Use NULL instead of 0

Use NULL instead of 0 for pointer variables.

Signed-off-by: Sachin Kamat <sachin.kamat@linaro.org>
Tested-by: Tobias Rauter <tobiasrauter@gmail.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

drivers/crypto/dcp.c

@@ -408,7 +408,7 @@ static void dcp_done_task(unsigned long data)
 	ablkcipher_walk_complete(&dev->ctx->walk);
 	dev->ctx->req->base.complete(&dev->ctx->req->base,
 			dev->ctx->stat);
-	dev->ctx->req = 0;
+	dev->ctx->req = NULL;
 	/* in case there are other requests in the queue */
 	tasklet_schedule(&dev->queue_task);
 }