[media] staging: media: cxd2099: fix sparse warnings in cxd2099_attach

The following sparse warnings were fixed

drivers/staging/media/cxd2099/cxd2099.c:686:26: warning: Using plain integer as NULL pointer
drivers/staging/media/cxd2099/cxd2099.c:691:24: warning: Using plain integer as NULL pointer
drivers/staging/media/cxd2099/cxd2099.c:696:24: warning: Using plain integer as NULL pointer

Signed-off-by: Devendra Naga <develkernel412222@gmail.com>
Cc: Ralph Metzler <rjkm@metzlerbros.de>
Cc: Oliver Endriss <o.endriss@gmx.de>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
diff --git a/drivers/staging/media/cxd2099/cxd2099.c b/drivers/staging/media/cxd2099/cxd2099.c
index 1c04185..1678503 100644
--- a/drivers/staging/media/cxd2099/cxd2099.c
+++ b/drivers/staging/media/cxd2099/cxd2099.c
@@ -683,17 +683,17 @@
 				      void *priv,
 				      struct i2c_adapter *i2c)
 {
-	struct cxd *ci = 0;
+	struct cxd *ci;
 	u8 val;
 
 	if (i2c_read_reg(i2c, cfg->adr, 0, &val) < 0) {
 		printk(KERN_INFO "No CXD2099 detected at %02x\n", cfg->adr);
-		return 0;
+		return NULL;
 	}
 
 	ci = kmalloc(sizeof(struct cxd), GFP_KERNEL);
 	if (!ci)
-		return 0;
+		return NULL;
 	memset(ci, 0, sizeof(*ci));
 
 	mutex_init(&ci->lock);