Remove xreadlines reference

Doc/lib/libbz2.tex

@@ -82,7 +82,7 @@ is an approximate bound on the total number of bytes in the lines returned.
 \begin{methoddesc}[BZ2File]{xreadlines}{}
 For backward compatibility. \class{BZ2File} objects now include the
 performance optimizations previously implemented in the
-\refmodule{xreadlines} module.
+\module{xreadlines} module.
 \deprecated{2.3}{This exists only for compatibility with the method by
                  this name on \class{file} objects, which is
                  deprecated.  Use \code{for line in file} instead.}