fix(behaviors): Prevent accidental transparent behavior return values.

Needed because k_work_reschedule can return positive success codes.

app/src/ext_power_generic.c

@@ -50,7 +50,8 @@ static struct k_work_delayable ext_power_save_work;
 
 int ext_power_save_state() {
 #if IS_ENABLED(CONFIG_SETTINGS)
-    return k_work_reschedule(&ext_power_save_work, K_MSEC(CONFIG_ZMK_SETTINGS_SAVE_DEBOUNCE));
+    int ret = k_work_reschedule(&ext_power_save_work, K_MSEC(CONFIG_ZMK_SETTINGS_SAVE_DEBOUNCE));
+    return MIN(ret, 0);
 #else
     return 0;
 #endif

app/src/rgb_underglow.c

@@ -272,7 +272,8 @@ static int zmk_rgb_underglow_init(const struct device *_arg) {
 
 int zmk_rgb_underglow_save_state() {
 #if IS_ENABLED(CONFIG_SETTINGS)
-    return k_work_reschedule(&underglow_save_work, K_MSEC(CONFIG_ZMK_SETTINGS_SAVE_DEBOUNCE));
+    int ret = k_work_reschedule(&underglow_save_work, K_MSEC(CONFIG_ZMK_SETTINGS_SAVE_DEBOUNCE));
+    return MIN(ret, 0);
 #else
     return 0;
 #endif