[PATCH -next] spi: spi-zynqmp-gqspi: Fix missing unlock on error in zynqmp_qspi_exec_op()

[Wei Yongjun]

Add the missing unlock before return from function zynqmp_qspi_exec_op()
in the error handling case.

Fixes: a0f65be6e880 ("spi: spi-zynqmp-gqspi: add mutex locking for exec_op")
Reported-by: Hulk Robot <hulkci at huawei.com>
Signed-off-by: Wei Yongjun <weiyongjun1 at huawei.com>
---
 drivers/spi/spi-zynqmp-gqspi.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/spi/spi-zynqmp-gqspi.c b/drivers/spi/spi-zynqmp-gqspi.c
index 9494da9aea40..1670b0aeaa23 100644
--- a/drivers/spi/spi-zynqmp-gqspi.c
+++ b/drivers/spi/spi-zynqmp-gqspi.c
@@ -965,8 +965,10 @@ static int zynqmp_qspi_exec_op(struct spi_mem *mem,
 
 	if (op->cmd.opcode) {
 		tmpbuf = kzalloc(op->cmd.nbytes, GFP_KERNEL | GFP_DMA);
-		if (!tmpbuf)
+		if (!tmpbuf) {
+			mutex_unlock(&xqspi->op_lock);
 			return -ENOMEM;
+		}
 		tmpbuf[0] = op->cmd.opcode;
 		reinit_completion(&xqspi->data_completion);
 		xqspi->txbuf = tmpbuf;