dmaengine/amba-pl08x: Check txd->llis_va before freeing dma_pool

In pl08x_free_txd(), check if pool is allocated successfully before freeing it.
Signed-off-by: Viresh Kumar <viresh.kumar@st.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

drivers/dma/amba-pl08x.c

@@ -803,7 +803,8 @@ static void pl08x_free_txd(struct pl08x_driver_data *pl08x,
 	struct pl08x_sg *dsg, *_dsg;
 
 	/* Free the LLI */
-	dma_pool_free(pl08x->pool, txd->llis_va, txd->llis_bus);
+	if (txd->llis_va)
+		dma_pool_free(pl08x->pool, txd->llis_va, txd->llis_bus);
 
 	pl08x->pool_ctr--;