Staging: atomisp: fix locking in alloc_user_pages()

We call this function with the lock held and should also return with the
lock held as well.  This one error path is not-consistent because we
should return without the lock held.
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/media/atomisp/pci/atomisp2/hmm/hmm_bo.c

@@ -1011,6 +1011,7 @@ static int alloc_user_pages(struct hmm_buffer_object *bo,
 		dev_err(atomisp_dev, "find_vma failed\n");
 		atomisp_kernel_free(bo->page_obj);
 		atomisp_kernel_free(pages);
+		mutex_lock(&bo->mutex);
 		return -EFAULT;
 	}
 	mutex_lock(&bo->mutex);