altos: Add default button return value from ao_button_get

This "can't" happen, but it's not unreasonable to have a default
return value.

Signed-off-by: Keith Packard <keithp@keithp.com>

diff --git a/src/drivers/ao_button.c b/src/drivers/ao_button.c
index 25c0cd5cea66b753813cd566102ce5ba6f7c9da9..cdf073524e1e8f4ffb5f232f255c5ef854de28fe 100644 (file)
--- a/src/drivers/ao_button.c
+++ b/src/drivers/ao_button.c
@@ -59,6 +59,7 @@ _ao_button_get(struct ao_debounce *debounce)
        case 4: return ao_button_value(4);
 #endif
        }
        case 4: return ao_button_value(4);
 #endif
        }

+       return 0;

 }
 
 static void
 }
 
 static void