i2c: imx-lpi2c: clean rx/tx buffers upon new message

When start sending a new message clear the Rx & Tx buffer pointers in
order to avoid using stale pointers.

Signed-off-by: Alexander Stein <alexander.stein@ew.tq-group.com>
Tested-by: Emanuele Ghidoli <emanuele.ghidoli@toradex.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

Author: tq-steina

drivers/i2c/busses/i2c-imx-lpi2c.c

@@ -463,6 +463,8 @@ static int lpi2c_imx_xfer(struct i2c_adapter *adapter,
 		if (num == 1 && msgs[0].len == 0)
 			goto stop;
 
+		lpi2c_imx->rx_buf = NULL;
+		lpi2c_imx->tx_buf = NULL;
 		lpi2c_imx->delivered = 0;
 		lpi2c_imx->msglen = msgs[i].len;
 		init_completion(&lpi2c_imx->complete);