media: usbvision: Adjust eight checks for null pointers

The script “checkpatch.pl” pointed information out like the following.

Comparison to NULL could be written !…

Thus fix the affected source code places.
Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

drivers/media/usb/usbvision/usbvision-video.c

@@ -904,7 +904,7 @@ static ssize_t usbvision_read(struct file *file, char __user *buf,
 	PDEBUG(DBG_IO, "%s: %ld bytes, noblock=%d", __func__,
 	       (unsigned long)count, noblock);
 
-	if (!USBVISION_IS_OPERATIONAL(usbvision) || (buf == NULL))
+	if (!USBVISION_IS_OPERATIONAL(usbvision) || !buf)
 		return -EFAULT;
 
 	/* This entry point is compatible with the mmap routines
@@ -1234,7 +1234,7 @@ static void usbvision_vdev_init(struct usb_usbvision *usbvision,
 {
 	struct usb_device *usb_dev = usbvision->dev;
 
-	if (usb_dev == NULL) {
+	if (!usb_dev) {
 		dev_err(&usbvision->dev->dev,
 			"%s: usbvision->dev is not set\n", __func__);
 		return;
@@ -1320,7 +1320,7 @@ static struct usb_usbvision *usbvision_alloc(struct usb_device *dev,
 	struct usb_usbvision *usbvision;
 
 	usbvision = kzalloc(sizeof(struct usb_usbvision), GFP_KERNEL);
-	if (usbvision == NULL)
+	if (!usbvision)
 		return NULL;
 
 	usbvision->dev = dev;
@@ -1334,7 +1334,7 @@ static struct usb_usbvision *usbvision_alloc(struct usb_device *dev,
 
 	/* prepare control urb for control messages during interrupts */
 	usbvision->ctrl_urb = usb_alloc_urb(USBVISION_URB_FRAMES, GFP_KERNEL);
-	if (usbvision->ctrl_urb == NULL)
+	if (!usbvision->ctrl_urb)
 		goto err_unreg;
 
 	return usbvision;
@@ -1380,7 +1380,7 @@ static void usbvision_configure_video(struct usb_usbvision *usbvision)
 {
 	int model;
 
-	if (usbvision == NULL)
+	if (!usbvision)
 		return;
 
 	model = usbvision->dev_model;
@@ -1474,7 +1474,7 @@ static int usbvision_probe(struct usb_interface *intf,
 	}
 
 	usbvision = usbvision_alloc(dev, intf);
-	if (usbvision == NULL) {
+	if (!usbvision) {
 		dev_err(&intf->dev, "%s: couldn't allocate USBVision struct\n", __func__);
 		ret = -ENOMEM;
 		goto err_usb;
@@ -1494,7 +1494,7 @@ static int usbvision_probe(struct usb_interface *intf,
 	usbvision->num_alt = uif->num_altsetting;
 	PDEBUG(DBG_PROBE, "Alternate settings: %i", usbvision->num_alt);
 	usbvision->alt_max_pkt_size = kmalloc(32 * usbvision->num_alt, GFP_KERNEL);
-	if (usbvision->alt_max_pkt_size == NULL) {
+	if (!usbvision->alt_max_pkt_size) {
 		ret = -ENOMEM;
 		goto err_pkt;
 	}
@@ -1565,7 +1565,7 @@ static void usbvision_disconnect(struct usb_interface *intf)
 
 	PDEBUG(DBG_PROBE, "");
 
-	if (usbvision == NULL) {
+	if (!usbvision) {
 		pr_err("%s: usb_get_intfdata() failed\n", __func__);
 		return;
 	}