Fix spelling mistake "succsefully" -> "successfully"

There is a spelling mistake in a puts statement. Fix it.

Signed-off-by: Colin Ian King <colin.i.king@gmail.com>
Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>

sysdeps/pthread/tst-stdio2.c

@@ -75,7 +75,7 @@ do_test (void)
       exit (1);
     }
 
-  puts ("join returned succsefully");
+  puts ("join returned successfully");
 
   return 0;
 }