mfd: fsl-imx25: Fix check for platform_get_irq() errors

The mx25_tsadc_remove() function assumes all non-zero returns are success
but the platform_get_irq() function returns negative on error and
positive non-zero values on success.  It never returns zero, but if it
did then treat that as a success.

Fixes: 18f77393 ("mfd: fsl-imx25: Clean up irq settings during removal")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Martin Kaiser <martin@kaiser.cx>
Signed-off-by: Lee Jones <lee@kernel.org>
Link: https://lore.kernel.org/r/YvTfkbVQWYKMKS/t@kili

drivers/mfd/fsl-imx25-tsadc.c

@@ -69,7 +69,7 @@ static int mx25_tsadc_setup_irq(struct platform_device *pdev,
 	int irq;
 
 	irq = platform_get_irq(pdev, 0);
-	if (irq <= 0)
+	if (irq < 0)
 		return irq;
 
 	tsadc->domain = irq_domain_add_simple(np, 2, 0, &mx25_tsadc_domain_ops,
@@ -89,7 +89,7 @@ static int mx25_tsadc_unset_irq(struct platform_device *pdev)
 	struct mx25_tsadc *tsadc = platform_get_drvdata(pdev);
 	int irq = platform_get_irq(pdev, 0);
 
-	if (irq) {
+	if (irq >= 0) {
 		irq_set_chained_handler_and_data(irq, NULL, NULL);
 		irq_domain_remove(tsadc->domain);
 	}