Ticket #1556: pthread.patch

pthread.h

@@ -21 +21 @@
 typedef struct  _pthread_barrierattr    *pthread_barrierattr_t;
 typedef struct  _pthread_spinlock   *pthread_spinlock_t;
 
-struct pthread_once {
+struct _pthread_once {
     int state;
     pthread_mutex_t mutex;
 };