[media] bt8xx: just return 0 instead of using a var

Instead of allocating a var to store 0 and just return it,
change the code to return 0 directly.

Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>

drivers/media/pci/bt8xx/dst_ca.c

@@ -674,11 +674,9 @@ static int dst_ca_release(struct inode *inode, struct file *file)
 
 static ssize_t dst_ca_read(struct file *file, char __user *buffer, size_t length, loff_t *offset)
 {
-	ssize_t bytes_read = 0;
-
 	dprintk(verbose, DST_CA_DEBUG, 1, " Device read.");
 
-	return bytes_read;
+	return 0;
 }
 
 static ssize_t dst_ca_write(struct file *file, const char __user *buffer, size_t length, loff_t *offset)