Throughout, remove extra space after function name from debugging output.

Throughout, change syscalls to report on return values using new %R format
option.
* smallprint.cc (__small_vsprintf): Add parsing for %R to report on return
values and possible errno from syscalls.
* errno.cc (errmap): Add PRIVILEGE_NOT_HELD.
* fhandler_tty.cc (fhandler_pty_master::setup): When creating a thread use
shorter name to reduce debuggging output.
* select.cc (start_thread_pipe): Ditto.
(start_thread_serial): Ditto.
(start_thread_socket): Ditto.
(start_thread_mailslot): Ditto.
* sigproc.cc (talktome): Ditto.

winsup/cygwin/sec_helper.cc

@@ -434,7 +434,7 @@ set_privilege (HANDLE token, DWORD privilege, bool enable)
 
 out:
   if (ret < 0)
-    debug_printf ("%d = set_privilege ((token %x) %W, %d)", ret, token,
+    debug_printf ("%d = set_privilege((token %x) %W, %d)", ret, token,
 		  privilege_name (new_priv.Privileges[0].Luid), enable);
   return ret;
 }