Correct checking for TV Download Dir deletion

processTV.processDir changes uses the real path of the dirName
given in the attribute, which expands all symbolic links. Later,
when it checks whether current post-processed folder should be
deleted, it tries to match the dirName against the
sickbeard.TV_DOWNLOAD_DIR, however the second path is not expanded
with os.path.realpath which results in an unmatched condition and
hence deletion of the TV Download Dir if the path given in the
configuration is a symbolic link.