Update example to no longer use the FCNTL module.
diff --git a/Doc/lib/libsignal.tex b/Doc/lib/libsignal.tex
index 11f0737..fe9b180 100644
--- a/Doc/lib/libsignal.tex
+++ b/Doc/lib/libsignal.tex
@@ -155,7 +155,7 @@
 sent, and the handler raises an exception.
 
 \begin{verbatim}
-import signal, os, FCNTL
+import signal, os
 
 def handler(signum, frame):
     print 'Signal handler called with signal', signum
@@ -166,7 +166,7 @@
 signal.alarm(5)
 
 # This open() may hang indefinitely
-fd = os.open('/dev/ttyS0', FCNTL.O_RDWR)  
+fd = os.open('/dev/ttyS0', os.O_RDWR)  
 
 signal.alarm(0)          # Disable the alarm
 \end{verbatim}