wait_for_completion_interruptible_timeout() may return negative value.
In this case, checking if (t > 0)  will return true if t is unsigned.
Signed-off-by: Axel Lin <axel.lin@gmail.com>
Acked-by: Lars-Peter Clausen <lars@metafoo.de>
Cc: stable@kernel.org (3.0+)
Signed-off-by: Guenter Roeck <guenter.roeck@ericsson.com>
 {
        struct jz4740_hwmon *hwmon = dev_get_drvdata(dev);
        struct completion *completion = &hwmon->read_completion;
-       unsigned long t;
+       long t;
        unsigned long val;
        int ret;