ds2782_battery: Fix ds2782_get_capacity return value

The ds2782_get_capacity function should return 0 on success, not the
capacity value.
Signed-off-by: Ryan Mallon <ryan@bluewatersys.com>
Signed-off-by: Anton Vorontsov <cbouatmailru@gmail.com>

drivers/power/ds2782_battery.c

@@ -163,7 +163,7 @@ static int ds2782_get_capacity(struct ds278x_info *info, int *capacity)
 	if (err)
 		return err;
 	*capacity = raw;
-	return raw;
+	return 0;
 }
 
 static int ds2786_get_current(struct ds278x_info *info, int *current_uA)