staging: most: cdev: avoid warning about potentially uninitialized variable

This patch avoids the warning that the pointer mbo might be used
uninitialized that some environmens throw.
Signed-off-by: Christian Gromm <christian.gromm@microchip.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/most/cdev/cdev.c

@@ -242,7 +242,7 @@ static ssize_t
 comp_read(struct file *filp, char __user *buf, size_t count, loff_t *offset)
 {
 	size_t to_copy, not_copied, copied;
-	struct mbo *mbo;
+	struct mbo *mbo = NULL;
 	struct comp_channel *c = filp->private_data;
 
 	mutex_lock(&c->io_mutex);