Networking: Correct the value returned by accept() in the case where net_lockingwait() is called. It was returning -1 and losing the errno value. Noted by Rony Xln

net/utils/net_lock.c

@@ -1,7 +1,7 @@
 /****************************************************************************
  * net/utils/net_lock.c
  *
- *   Copyright (C) 2011-2012, 2014 Gregory Nutt. All rights reserved.
+ *   Copyright (C) 2011-2012, 2014-2015 Gregory Nutt. All rights reserved.
  *   Author: Gregory Nutt <gnutt@nuttx.org>
  *
  * Redistribution and use in source and binary forms, with or without
@@ -178,6 +178,14 @@ void net_unlock(net_lock_t flags)
  * Description:
  *   Atomically wait for sem while temporarily releasing g_netlock.
  *
+ * Input Parameters:
+ *   sem - A reference to the semaphore to be taken.
+ *
+ * Returned value:
+ *   The returned value is the same as sem_wait():  Zero (OK) is returned
+ *   on success; -1 (ERROR) is returned on a failure with the errno value
+ *   set appropriately.
+ *
  ****************************************************************************/
 
 int net_lockedwait(sem_t *sem)