I2C: OMAP: Don't check if wait_for_completion_timeout() returns less than zero

By definition, wait_for_completion_timeout() returns an unsigned value and
therefore, it is not necessary to check if the return value is less than zero
as this is not possible.

This is based on a patch from Jon Hunter <jon-hunter@ti.com>
Changes from his patch
- Declare a long as the wait_for_completion_timeout returns long.

Original patch is
http://git.omapzoom.org/?p=kernel/omap.git;a=commitdiff;h=ea02cece7b0000bc736e60c4188a11aaa74bc6e6

Reviewed-by: Kevin Hilman <khilman@ti.com>
Signed-off-by: Jon Hunter <jon-hunter@ti.com>
Signed-off-by: Shubhrajyoti D <shubhrajyoti@ti.com>
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>

drivers/i2c/busses/i2c-omap.c

@@ -473,7 +473,7 @@ static int omap_i2c_xfer_msg(struct i2c_adapter *adap,
 			     struct i2c_msg *msg, int stop)
 {
 	struct omap_i2c_dev *dev = i2c_get_adapdata(adap);
-	int r;
+	unsigned long timeout;
 	u16 w;
 
 	dev_dbg(dev->dev, "addr: 0x%04x, len: %d, flags: 0x%x, stop: %d\n",
@@ -541,12 +541,10 @@ static int omap_i2c_xfer_msg(struct i2c_adapter *adap,
 	 * REVISIT: We should abort the transfer on signals, but the bus goes
 	 * into arbitration and we're currently unable to recover from it.
 	 */
-	r = wait_for_completion_timeout(&dev->cmd_complete,
-					OMAP_I2C_TIMEOUT);
+	timeout = wait_for_completion_timeout(&dev->cmd_complete,
+						OMAP_I2C_TIMEOUT);
 	dev->buf_len = 0;
-	if (r < 0)
-		return r;
-	if (r == 0) {
+	if (timeout == 0) {
 		dev_err(dev->dev, "controller timed out\n");
 		omap_i2c_init(dev);
 		return -ETIMEDOUT;