psxsignal06: Fix bug where mutex not locked and add EPERM error check

This test formerly had a bug in that it attempted to wait on a
    condition variable with a Mutex that was not locked. This is
    undefined by POSIX. But a recent change to match GNU/Linux behavior
    resulted in finding a bug in the test.

testsuites/psxtests/psxsignal06/init.c

@@ -1,5 +1,5 @@
 /*
- *  COPYRIGHT (c) 1989-2012.
+ *  COPYRIGHT (c) 1989-2013.
  *  On-Line Applications Research Corporation (OAR).
  *
  *  The license and distribution terms for this file may be
@@ -56,6 +56,9 @@ void *TestThread(
   act.sa_flags   = 0;
   sigaction( SIGUSR1, &act, NULL );
 
+  status = pthread_mutex_lock( &MutexId );
+  rtems_test_assert(  !status );
+
   /* interrupting condition wait returns 0 */
   puts( "Test: pthread_cond_wait - OK" );
   status = pthread_cond_wait( &CondVarId, &MutexId );