fix tiff identification

git-svn-id: http://tesseract-ocr.googlecode.com/svn/trunk@934 d0cd1f9f-072b-0410-8dd7-cf729c803f20
produce only one output file in case of hocr

git-svn-id: http://tesseract-ocr.googlecode.com/svn/trunk@935 d0cd1f9f-072b-0410-8dd7-cf729c803f20