Fixed minor markup nits for consistency with the rest of the library

reference.

Doc/lib/libstat.tex

@@ -117,11 +117,11 @@ The interpretation of ``file size'' changes according to the file
 type.  For plain files this is the size of the file in bytes.  For
 FIFOs and sockets under most Unixes (including Linux in particular),
 the ``size'' is the number of bytes waiting to be read at the time of
-the stat(2)/fstat(2)/lstat(2) call; this can sometimes be useful,
-especially for polling one of these special files after a non-blocking
-open.  The meaning of the size field for other character and block
-devices varies more, depending on the local implementation of the
-underlying system call.
+the call to \function{os.stat()}, \function{os.fstat()}, or
+\function{os.lstat()}; this can sometimes be useful, especially for
+polling one of these special files after a non-blocking open.  The
+meaning of the size field for other character and block devices varies
+more, depending on the implementation of the underlying system call.
 
 Example: