Fix offset in memory when copying from/to OpenCL

src/drivers/opencl/driver_opencl.c

@@ -383,7 +383,7 @@ cl_int starpu_opencl_copy_async_sync(uintptr_t src, unsigned src_node, uintptr_t
 	case _STARPU_MEMORY_NODE_TUPLE(STARPU_OPENCL_RAM,STARPU_CPU_RAM):
 		err = starpu_opencl_copy_opencl_to_ram(
 				(cl_mem) src, src_node,
-				(void*) dst, dst_node,
+				(void*) dst + offset, dst_node,
 				size, offset, event, &ret);
 		if (STARPU_UNLIKELY(err))
 			STARPU_OPENCL_REPORT_ERROR(err);
@@ -391,7 +391,7 @@ cl_int starpu_opencl_copy_async_sync(uintptr_t src, unsigned src_node, uintptr_t
 
 	case _STARPU_MEMORY_NODE_TUPLE(STARPU_CPU_RAM,STARPU_OPENCL_RAM):
 		err = starpu_opencl_copy_ram_to_opencl(
-				(void*) src, src_node,
+				(void*) src + offset, src_node,
 				(cl_mem) dst, dst_node,
 				size, offset, event, &ret);
 		if (STARPU_UNLIKELY(err))