spi/mpc8xxx: don't check platform_get_irq's return value against zero

platform_get_irq returns -ENXIO on failure, so !irq was probably
always true.  Make irq a signed variable and compare irq <= 0.  Note
that a return value of zero is still handled as error even though this
could mean irq0.

This is a followup to 305b3228f9ff4d59f49e6d34a7034d44ee8ce2f0 that
changed the return value of platform_get_irq from 0 to -ENXIO on error.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Acked-by: Anton Vorontsov <avorontsov@ru.mvista.com>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>

1 files changed, 2 insertions, 2 deletions

diff --git a/drivers/spi/spi_mpc8xxx.c b/drivers/spi/spi_mpc8xxx.c
index 1fb2a6ea328c..08065fb15817 100644
--- a/drivers/spi/spi_mpc8xxx.c
+++ b/drivers/spi/spi_mpc8xxx.c
@@ -1328,7 +1328,7 @@ static struct of_platform_driver of_mpc8xxx_spi_driver = {
 static int __devinit plat_mpc8xxx_spi_probe(struct platform_device *pdev)
 {
         struct resource *mem;
-        unsigned int irq;
+        int irq;
         struct spi_master *master;
 
         if (!pdev->dev.platform_data)
@@ -1339,7 +1339,7 @@ static int __devinit plat_mpc8xxx_spi_probe(struct platform_device *pdev)
                 return -EINVAL;
 
         irq = platform_get_irq(pdev, 0);
-        if (!irq)
+        if (irq <= 0)
                 return -EINVAL;
 
         master = mpc8xxx_spi_probe(&pdev->dev, mem, irq);