staging/ozwpan: Fix NULL vs zero in ozeltbuf.c (sparse warning)

This patch fixes the warning "Using plain integer as NULL pointer",
generated by sparse, by replacing the offending 0s with NULL.

If the initialization with NULL was unnecessary (due to unconditional
assignment before first use) it was removed.
Signed-off-by: Peter Huewe <peterhuewe@gmx.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/ozwpan/ozeltbuf.c

@@ -64,7 +64,7 @@ void oz_elt_buf_term(struct oz_elt_buf *buf)
  */
 struct oz_elt_info *oz_elt_info_alloc(struct oz_elt_buf *buf)
 {
-	struct oz_elt_info *ei = 0;
+	struct oz_elt_info *ei = NULL;
 	spin_lock_bh(&buf->lock);
 	if (buf->free_elts && buf->elt_pool) {
 		ei = container_of(buf->elt_pool, struct oz_elt_info, link);
@@ -82,9 +82,9 @@ struct oz_elt_info *oz_elt_info_alloc(struct oz_elt_buf *buf)
 	if (ei) {
 		ei->flags = 0;
 		ei->app_id = 0;
-		ei->callback = 0;
+		ei->callback = NULL;
 		ei->context = 0;
-		ei->stream = 0;
+		ei->stream = NULL;
 		ei->magic = OZ_ELT_INFO_MAGIC_USED;
 		INIT_LIST_HEAD(&ei->link);
 		INIT_LIST_HEAD(&ei->link_order);
@@ -135,7 +135,7 @@ int oz_elt_stream_create(struct oz_elt_buf *buf, u8 id, int max_buf_count)
 	oz_trace("oz_elt_stream_create(0x%x)\n", id);
 
 	st = kzalloc(sizeof(struct oz_elt_stream), GFP_ATOMIC | __GFP_ZERO);
-	if (st == 0)
+	if (st == NULL)
 		return -ENOMEM;
 	atomic_set(&st->ref_count, 1);
 	st->id = id;
@@ -151,7 +151,7 @@ int oz_elt_stream_create(struct oz_elt_buf *buf, u8 id, int max_buf_count)
 int oz_elt_stream_delete(struct oz_elt_buf *buf, u8 id)
 {
 	struct list_head *e;
-	struct oz_elt_stream *st;
+	struct oz_elt_stream *st = NULL;
 	oz_trace("oz_elt_stream_delete(0x%x)\n", id);
 	spin_lock_bh(&buf->lock);
 	e = buf->stream_list.next;
@@ -161,7 +161,7 @@ int oz_elt_stream_delete(struct oz_elt_buf *buf, u8 id)
 			list_del(e);
 			break;
 		}
-		st = 0;
+		st = NULL;
 	}
 	if (!st) {
 		spin_unlock_bh(&buf->lock);
@@ -208,7 +208,7 @@ void oz_elt_stream_put(struct oz_elt_stream *st)
 int oz_queue_elt_info(struct oz_elt_buf *buf, u8 isoc, u8 id,
 	struct oz_elt_info *ei)
 {
-	struct oz_elt_stream *st = 0;
+	struct oz_elt_stream *st = NULL;
 	struct list_head *e;
 	if (id) {
 		list_for_each(e, &buf->stream_list) {
@@ -297,7 +297,7 @@ int oz_select_elts_for_tx(struct oz_elt_buf *buf, u8 isoc, unsigned *len,
 					"Stream down: %d  %d\n",
 					ei->stream->buf_count, ei->length);
 				oz_elt_stream_put(ei->stream);
-				ei->stream = 0;
+				ei->stream = NULL;
 			}
 			INIT_LIST_HEAD(&ei->link_order);
 			list_add_tail(&ei->link, list);
@@ -319,7 +319,7 @@ int oz_are_elts_available(struct oz_elt_buf *buf)
  */
 void oz_trim_elt_pool(struct oz_elt_buf *buf)
 {
-	struct list_head *free = 0;
+	struct list_head *free = NULL;
 	struct list_head *e;
 	spin_lock_bh(&buf->lock);
 	while (buf->free_elts > buf->max_free_elts) {