habanalabs: missing mutex_unlock in process kill procedure

missing mutex unlock once driver is giving up killing user processes.
Signed-off-by: Ofir Bitton <obitton@habana.ai>
Reviewed-by: Oded Gabbay <ogabbay@kernel.org>
Signed-off-by: Oded Gabbay <ogabbay@kernel.org>

drivers/misc/habanalabs/common/device.c

@@ -822,6 +822,7 @@ static int device_kill_open_processes(struct hl_device *hdev, u32 timeout)
 		} else {
 			dev_warn(hdev->dev,
 				"Can't get task struct for PID so giving up on killing process\n");
+			mutex_unlock(&hdev->fpriv_list_lock);
 			return -ETIME;
 		}
 	}