[media] s5p-tv: fix wait_event_timeout return handling

event API conformance testing with coccinelle spatches are being
used to locate API usage inconsistencies this triggert with:
./drivers/media/platform/s5p-tv/mixer_reg.c:364
        incorrect check for negative return

Return type of wait_event_timeout is signed long not int and the
return type is >=0 always thus the negative check is unnecessary.
An appropriately named variable of type long is inserted and the
call fixed up aswell as the negative return check dropped.
Signed-off-by: Nicholas Mc Guire <hofrat@osadl.org>
Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>

drivers/media/platform/s5p-tv/mixer_reg.c

@@ -357,17 +357,15 @@ void mxr_reg_streamoff(struct mxr_device *mdev)
 
 int mxr_reg_wait4vsync(struct mxr_device *mdev)
 {
-	int ret;
+	long time_left;
 
 	clear_bit(MXR_EVENT_VSYNC, &mdev->event_flags);
 	/* TODO: consider adding interruptible */
-	ret = wait_event_timeout(mdev->event_queue,
+	time_left = wait_event_timeout(mdev->event_queue,
 			test_bit(MXR_EVENT_VSYNC, &mdev->event_flags),
 				 msecs_to_jiffies(1000));
-	if (ret > 0)
+	if (time_left > 0)
 		return 0;
-	if (ret < 0)
-		return ret;
 	mxr_warn(mdev, "no vsync detected - timeout\n");
 	return -ETIME;
 }