drivers/message/i2o/exec-osm.c: add missing mutex_unlock

Add a mutex_unlock missing on the error path.

The semantic match that finds this problem is as follows:
(http://coccinelle.lip6.fr/)

// <smpl>
@@
expression E1;
@@

* mutex_lock(E1,...);
  <+... when != E1
  if (...) {
    ... when != E1
*   return ...;
  }
  ...+>
* mutex_unlock(E1,...);
// </smpl>
Signed-off-by: Julia Lawall <julia@diku.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drivers/message/i2o/exec-osm.c

@@ -389,12 +389,16 @@ static int i2o_exec_lct_notify(struct i2o_controller *c, u32 change_ind)
 	dev = &c->pdev->dev;
 
 	if (i2o_dma_realloc(dev, &c->dlct,
-					le32_to_cpu(sb->expected_lct_size)))
+					le32_to_cpu(sb->expected_lct_size))) {
+		mutex_unlock(&c->lct_lock);
 		return -ENOMEM;
+	}
 
 	msg = i2o_msg_get_wait(c, I2O_TIMEOUT_MESSAGE_GET);
-	if (IS_ERR(msg))
+	if (IS_ERR(msg)) {
+		mutex_unlock(&c->lct_lock);
 		return PTR_ERR(msg);
+	}
 
 	msg->u.head[0] = cpu_to_le32(EIGHT_WORD_MSG_SIZE | SGL_OFFSET_6);
 	msg->u.head[1] = cpu_to_le32(I2O_CMD_LCT_NOTIFY << 24 | HOST_TID << 12 |