fix warnings

src/drivers/mpi/driver_mpi_common.c

@@ -252,7 +252,7 @@ void _starpu_mpi_common_mp_recv(const struct _starpu_mp_node *node, void *msg, i
 }
 
 /* SEND to any node */
-void _starpu_mpi_common_send_to_device(const struct _starpu_mp_node *node, int dst_devid, void *msg, int len, void * event)
+void _starpu_mpi_common_send_to_device(const struct _starpu_mp_node *node STARPU_ATTRIBUTE_UNUSED, int dst_devid, void *msg, int len, void * event)
 {
         int res;
         int id_proc;
@@ -293,7 +293,7 @@ void _starpu_mpi_common_send_to_device(const struct _starpu_mp_node *node, int d
 }
 
 /* RECV to any node */
-void _starpu_mpi_common_recv_from_device(const struct _starpu_mp_node *node, int src_devid, void *msg, int len, void * event)
+void _starpu_mpi_common_recv_from_device(const struct _starpu_mp_node *node STARPU_ATTRIBUTE_UNUSED, int src_devid, void *msg, int len, void * event)
 {
         int res;
         int id_proc;

src/drivers/mpi/driver_mpi_source.c

@@ -66,7 +66,7 @@ void _starpu_mpi_source_init(struct _starpu_mp_node *node)
         //TODO
 }
 
-void _starpu_mpi_source_deinit(struct _starpu_mp_node *node)
+void _starpu_mpi_source_deinit(struct _starpu_mp_node *node STARPU_ATTRIBUTE_UNUSED)
 {
 
 }