If not all the functions in the header are used, we'd get warnings about
them being unused. Mark all the functions as unused, so we can avoid
warnings.
In file included from tests/enroll.c:29:0:
pam/fingerprint-strings.h: In function ‘finger_str_to_msg’:
pam/fingerprint-strings.h:99:6: error: format not a string literal, argument types not checked [-Werror=format-nonliteral]
return g_strdup_printf (TR (fingers[i].place_str_specific), driver_name);
^~~~~~
pam/fingerprint-strings.h:104:6: error: format not a string literal, argument types not checked [-Werror=format-nonliteral]
return g_strdup_printf (TR (fingers[i].swipe_str_specific), driver_name);
^~~~~~
