USB: "sparse" cleanups for usb gadgets

This removes complaints about the gadget stack which are generated by
the currrent "sparse":  it doesn't like the fact that zero is the null
pointer.  (Last I checked, C guarantees that's correct ...)
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/usb/gadget/config.c

@@ -50,7 +50,7 @@ usb_descriptor_fillbuf(void *buf, unsigned buflen,
 		return -EINVAL;
 
 	/* fill buffer from src[] until null descriptor ptr */
-	for (; 0 != *src; src++) {
+	for (; NULL != *src; src++) {
 		unsigned		len = (*src)->bLength;
 
 		if (len > buflen)

drivers/usb/gadget/epautoconf.c

@@ -71,7 +71,7 @@ ep_matches (
 	u16		max;
 
 	/* endpoint already claimed? */
-	if (0 != ep->driver_data)
+	if (NULL != ep->driver_data)
 		return 0;
 
 	/* only support ep0 for portable CONTROL traffic */

drivers/usb/gadget/ether.c

@@ -1723,7 +1723,8 @@ rx_submit (struct eth_dev *dev, struct usb_request *req, gfp_t gfp_flags)
 		size += sizeof (struct rndis_packet_msg_type);
 	size -= size % dev->out_ep->maxpacket;
 
-	if ((skb = alloc_skb (size + NET_IP_ALIGN, gfp_flags)) == 0) {
+	skb = alloc_skb(size + NET_IP_ALIGN, gfp_flags);
+	if (skb == NULL) {
 		DEBUG (dev, "no rx skb\n");
 		goto enomem;
 	}

drivers/usb/gadget/inode.c

@@ -964,7 +964,7 @@ static int setup_req (struct usb_ep *ep, struct usb_request *req, u16 len)
 	}
 	if (len > sizeof (dev->rbuf))
 		req->buf = kmalloc(len, GFP_ATOMIC);
-	if (req->buf == 0) {
+	if (req->buf == NULL) {
 		req->buf = dev->rbuf;
 		return -ENOMEM;
 	}
@@ -1394,7 +1394,7 @@ gadgetfs_setup (struct usb_gadget *gadget, const struct usb_ctrlrequest *ctrl)
 	dev->setup_abort = 0;
 	if (dev->state == STATE_DEV_UNCONNECTED) {
 #ifdef	CONFIG_USB_GADGET_DUALSPEED
-		if (gadget->speed == USB_SPEED_HIGH && dev->hs_config == 0) {
+		if (gadget->speed == USB_SPEED_HIGH && dev->hs_config == NULL) {
 			spin_unlock(&dev->lock);
 			ERROR (dev, "no high speed config??\n");
 			return -EINVAL;

drivers/usb/gadget/m66592-udc.c

@@ -1299,7 +1299,7 @@ static int m66592_queue(struct usb_ep *_ep, struct usb_request *_req,
 	req->req.actual = 0;
 	req->req.status = -EINPROGRESS;
 
-	if (ep->desc == 0)	/* control */
+	if (ep->desc == NULL)	/* control */
 		start_ep0(ep, req);
 	else {
 		if (request && !ep->busy)

drivers/usb/gadget/zero.c

@@ -653,7 +653,8 @@ set_source_sink_config (struct zero_dev *dev, gfp_t gfp_flags)
 			result = usb_ep_enable (ep, d);
 			if (result == 0) {
 				ep->driver_data = dev;
-				if (source_sink_start_ep (ep, gfp_flags) != 0) {
+				if (source_sink_start_ep(ep, gfp_flags)
+						!= NULL) {
 					dev->in_ep = ep;
 					continue;
 				}
@@ -667,7 +668,8 @@ set_source_sink_config (struct zero_dev *dev, gfp_t gfp_flags)
 			result = usb_ep_enable (ep, d);
 			if (result == 0) {
 				ep->driver_data = dev;
-				if (source_sink_start_ep (ep, gfp_flags) != 0) {
+				if (source_sink_start_ep(ep, gfp_flags)
+						!= NULL) {
 					dev->out_ep = ep;
 					continue;
 				}