Fixed index references to modules.

Made references to files use \file{} instead of \code{}.
diff --git a/Doc/libfcntl.tex b/Doc/libfcntl.tex
index b76a28c..21f2514 100644
--- a/Doc/libfcntl.tex
+++ b/Doc/libfcntl.tex
@@ -48,11 +48,11 @@
 \end{funcdesc}
 
 If the library modules \code{FCNTL} or \code{IOCTL} are missing, you
-can find the opcodes in the C include files \code{sys/fcntl} and
-\code{sys/ioctl}. You can create the modules yourself with the h2py
-script, found in the \code{Tools/scripts} directory.
-\stmodindex{FCNTL}
-\stmodindex{IOCTL}
+can find the opcodes in the C include files \file{sys/fcntl.h} and
+\file{sys/ioctl.h}. You can create the modules yourself with the h2py
+script, found in the \file{Tools/scripts} directory.
+\refstmodindex{FCNTL}
+\refstmodindex{IOCTL}
 
 Examples (all on a SVR4 compliant system):