[script][pad_figure] Fix name

bob/pad/base/script/pad_figure.py

@@ -46,7 +46,7 @@ class Hist(measure_figure.Hist):
     def _setup_hist(self, neg, pos):
         self._title_base = 'PAD'
         self._density_hist(
-            pos[0], n=0, label='Bona fide', color='C1'
+            pos[0], n=0, label='Bona-fide', color='C1'
         )
         self._density_hist(
             neg[0], n=1, label='Presentation attack', alpha=0.4, color='C7',