i2c: jz4780: add IRQ check

The driver neglects to check the result of platform_get_irq()'s call and
blithely passes the negative error codes to devm_request_irq() (which
takes *unsigned* IRQ #), causing it to fail with -EINVAL, overriding
an original error code.  Stop calling devm_request_irq() with invalid
IRQ #s.

Fixes: ba92222ed6 ("i2c: jz4780: Add i2c bus controller driver for Ingenic JZ4780")
Signed-off-by: Sergey Shtylyov <s.shtylyov@omprussia.ru>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

drivers/i2c/busses/i2c-jz4780.c

@@ -825,7 +825,10 @@ static int jz4780_i2c_probe(struct platform_device *pdev)
 
 	jz4780_i2c_writew(i2c, JZ4780_I2C_INTM, 0x0);
 
-	i2c->irq = platform_get_irq(pdev, 0);
+	ret = platform_get_irq(pdev, 0);
+	if (ret < 0)
+		goto err;
+	i2c->irq = ret;
 	ret = devm_request_irq(&pdev->dev, i2c->irq, jz4780_i2c_irq, 0,
 			       dev_name(&pdev->dev), i2c);
 	if (ret)