[PATCH] os: Add -displayfd into -help text

[Robert Ancell]

Add -displayfd into -help text. It was mentioned in the man page but seem to have been missed from the -help text.
---
 os/utils.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/os/utils.c b/os/utils.c
index 60e828e..1555dbd 100644
--- a/os/utils.c
+++ b/os/utils.c
@@ -501,6 +501,7 @@ UseMsg(void)
     ErrorF("-cc int                default color visual class\n");
     ErrorF("-nocursor              disable the cursor\n");
     ErrorF("-core                  generate core dump on fatal error\n");
+    ErrorF("-displayfd fd          file descriptor to write display number to when ready to connect\n");
     ErrorF("-dpi int               screen resolution in dots per inch\n");
 #ifdef DPMSExtension
     ErrorF("-dpms                  disables VESA DPMS monitor control\n");
-- 
1.9.1