mtd: spear_smi: failure test for null rather than negative integer

dev_get_platdata returns a pointer, so the failure value would be NULL
rather than a negative integer.

The semantic match that finds this problem is: (http://coccinelle.lip6.fr/)

// <smpl>
@@
expression x,e;
statement S1,S2;
@@

*x = dev_get_platdata(...)
... when != x = e
*if (x < 0) S1 else S2
// </smpl>
Signed-off-by: NJulia Lawall <Julia.Lawall@lip6.fr>
Acked-by: NStefan Roese <sr@denx.de>
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

drivers/mtd/devices/spear_smi.c

@@ -935,7 +935,7 @@ static int __devinit spear_smi_probe(struct platform_device *pdev)
 		}
 	} else {
 		pdata = dev_get_platdata(&pdev->dev);
-		if (pdata < 0) {
+		if (!pdata) {
 			ret = -ENODEV;
 			dev_err(&pdev->dev, "no platform data\n");
 			goto err;