chdkcamera: Fix show_textbox method
chdkcamera: Fix show_textbox method

nafraf/spreads,gareth8118/spreads,miloh/spreads,miloh/spreads,DIYBookScanner/spreads,DIYBookScanner/spreads,gareth8118/spreads,gareth8118/spreads,adongy/spreads,adongy/spreads,adongy/spreads,nafraf/spreads,DIYBookScanner/spreads,miloh/spreads,nafraf/spreads