Windows : Fix application verifier errors.

Make different threads that are running data_copy_thread_func()
use the same pthread_mutex for locking (not the copies of the same
pthread_mutex_t).

extra/mariabackup/backup_copy.cc

@@ -124,7 +124,7 @@ struct datadir_thread_ctxt_t {
 	datadir_iter_t		*it;
 	uint			n_thread;
 	uint			*count;
-	pthread_mutex_t		count_mutex;
+	pthread_mutex_t*	count_mutex;
 	os_thread_id_t		id;
 	bool			ret;
 };
@@ -965,7 +965,7 @@ run_data_threads(datadir_iter_t *it, os_thread_func_t func, uint n)
 		data_threads[i].it = it;
 		data_threads[i].n_thread = i + 1;
 		data_threads[i].count = &count;
-		data_threads[i].count_mutex = count_mutex;
+		data_threads[i].count_mutex = &count_mutex;
 		os_thread_create(func, data_threads + i, &data_threads[i].id);
 	}
 
@@ -2042,9 +2042,9 @@ decrypt_decompress_thread_func(void *arg)
 
 	datadir_node_free(&node);
 
-	pthread_mutex_lock(&ctxt->count_mutex);
+	pthread_mutex_lock(ctxt->count_mutex);
 	--(*ctxt->count);
-	pthread_mutex_unlock(&ctxt->count_mutex);
+	pthread_mutex_unlock(ctxt->count_mutex);
 
 	ctxt->ret = ret;
 

extra/mariabackup/xtrabackup.cc

@@ -696,7 +696,7 @@ typedef struct {
 	datafiles_iter_t 	*it;
 	uint			num;
 	uint			*count;
-	pthread_mutex_t		count_mutex;
+	pthread_mutex_t*	count_mutex;
 	os_thread_id_t		id;
 } data_thread_ctxt_t;
 
@@ -2874,9 +2874,9 @@ data_copy_thread_func(
 
 	}
 
-	pthread_mutex_lock(&ctxt->count_mutex);
+	pthread_mutex_lock(ctxt->count_mutex);
 	(*ctxt->count)--;
-	pthread_mutex_unlock(&ctxt->count_mutex);
+	pthread_mutex_unlock(ctxt->count_mutex);
 
 	my_thread_end();
 	os_thread_exit();
@@ -4338,7 +4338,7 @@ xtrabackup_backup_func()
 		data_threads[i].it = it;
 		data_threads[i].num = i+1;
 		data_threads[i].count = &count;
-		data_threads[i].count_mutex = count_mutex;
+		data_threads[i].count_mutex = &count_mutex;
 		os_thread_create(data_copy_thread_func, data_threads + i,
 				 &data_threads[i].id);
 	}