LibC: Fix shared pthread_barrier init

Initialize internal lock and cond as shared when the barrier is shared

userspace/libraries/LibC/include/bits/types/pthread_types.h

@@ -54,7 +54,6 @@ typedef struct
 } pthread_barrierattr_t;
 typedef struct
 {
-	pthread_barrierattr_t attr;
 	pthread_mutex_t lock;
 	pthread_cond_t cond;
 	unsigned target;