Need to reset the max line length after calling svn_io_read_length_line().
Need to reset the max line length after calling svn_io_read_length_line().

* subversion/libsvn_fs_fs/fs_fs.c
  (read_change): svn_io_read_length_line() changes len to the size read in the
    previous call, we need to reset it back to our buffer size before calling
    svn_io_read_length_line() again.

jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion