Staging: lirc, fix lock imbalance

[2nd version -- melded all three together]

1) There is a missing return or goto statement in one fail path in
sasem_probe, so that the code contiues its normal execution (and
unlocks a mutex twice). Fix that by jumping to the right place.

Anyway the code is very broken on its fail paths and there are many
leaks. But that's a different story.

2) There is an omitted unlock in one fail path in vfd_write, jump to
the right place to unlock the lock.

3) In the probe function, there is one more error where the lock is
not unlocked. Fix that by jumping to the proper place.
Signed-off-by: NJiri Slaby <jslaby@suse.cz>
Cc: Jarod Wilson <jarod@redhat.com>
Cc: Mauro Carvalho Chehab <mchehab@redhat.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

drivers/staging/lirc/lirc_sasem.c

@@ -386,8 +386,10 @@ static ssize_t vfd_write(struct file *file, const char *buf,
 	}
 
 	data_buf = memdup_user(buf, n_bytes);
-	if (PTR_ERR(data_buf))
-		return PTR_ERR(data_buf);
+	if (PTR_ERR(data_buf)) {
+		retval = PTR_ERR(data_buf);
+		goto exit;
+	}
 
 	memcpy(context->tx.data_buf, data_buf, n_bytes);
 
@@ -803,7 +805,8 @@ static int sasem_probe(struct usb_interface *interface,
 	if (lirc_minor < 0) {
 		err("%s: lirc_register_driver failed", __func__);
 		alloc_status = 7;
-		mutex_unlock(&context->ctx_lock);
+		retval = lirc_minor;
+		goto unlock;
 	} else
 		printk(KERN_INFO "%s: Registered Sasem driver (minor:%d)\n",
 			__func__, lirc_minor);
@@ -828,7 +831,7 @@ static int sasem_probe(struct usb_interface *interface,
 		context = NULL;
 	case 1:
 		retval = -ENOMEM;
-		goto exit;
+		goto unlock;
 	}
 
 	/* Needed while unregistering! */
@@ -859,7 +862,7 @@ static int sasem_probe(struct usb_interface *interface,
 
 	printk(KERN_INFO "%s: Sasem device on usb<%d:%d> initialized\n",
 			__func__, dev->bus->busnum, dev->devnum);
-
+unlock:
 	mutex_unlock(&context->ctx_lock);
 exit:
 	return retval;