do not export fetch_data

src/datawizard/coherency.c

@@ -160,7 +160,7 @@ enomem:
 	return -ENOMEM;
 }
 
-int fetch_data(data_state *state, starpu_access_mode mode)
+static int fetch_data(data_state *state, starpu_access_mode mode)
 {
 	int ret;
 	uint32_t requesting_node = get_local_memory_node(); 

src/datawizard/coherency.h

@@ -135,8 +135,6 @@ typedef struct starpu_data_state_t {
 
 void display_msi_stats(void);
 
-__attribute__((warn_unused_result))
-int fetch_data(data_state *state, starpu_access_mode mode);
 //void release_data(data_state *state, uint32_t write_through_mask);
 
 __attribute__((warn_unused_result))