staging: kpc2000: double unlock in error handling in kpc_dma_transfer()

The goto err_descr_too_many; calls unlock_engine() so this unlocks
twice.

Fixes: 7df9529 ("staging: kpc2000: Add DMA driver")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/kpc2000/kpc_dma/fileops.c

@@ -116,13 +116,11 @@ int  kpc_dma_transfer(struct dev_private_data *priv, struct kiocb *kcb, unsigned
 	if (desc_needed >= ldev->desc_pool_cnt){
 		dev_warn(&priv->ldev->pldev->dev, "    mapped_entry_count = %d    num_descrs_needed = %d    num_descrs_avail = %d    TOO MANY to ever complete!\n", acd->mapped_entry_count, desc_needed, num_descrs_avail);
 		rv = -EAGAIN;
-		unlock_engine(ldev);
 		goto err_descr_too_many;
 	}
 	if (desc_needed > num_descrs_avail){
 		dev_warn(&priv->ldev->pldev->dev, "    mapped_entry_count = %d    num_descrs_needed = %d    num_descrs_avail = %d    Too many to complete right now.\n", acd->mapped_entry_count, desc_needed, num_descrs_avail);
 		rv = -EMSGSIZE;
-		unlock_engine(ldev);
 		goto err_descr_too_many;
 	}