chore(epicardium-modules): Fix all warnings

Fix all warnings in epicardium/modules.

Signed-off-by: Rahix <rahix@rahix.de>

epicardium/modules/bhi.c

@@ -227,7 +227,7 @@ out_free_i2c:
 
 void epic_bhi160_disable_all_sensors()
 {
-	for (int i = 0; i < sizeof(bhi160_sensor_active); i++) {
+	for (size_t i = 0; i < sizeof(bhi160_sensor_active); i++) {
 		if (bhi160_sensor_active[i]) {
 			epic_bhi160_disable_sensor(i);
 		}

epicardium/modules/personal_state.c

@@ -18,7 +18,7 @@ int personal_state_enabled()
 
 int epic_personal_state_set(uint8_t state, bool persistent)
 {
-	if (state < STATE_NONE || state > STATE_CAMP)
+	if (state > STATE_CAMP)
 		return -EINVAL;
 
 	led_animation_state = 0;

epicardium/modules/sleep.c

@@ -142,8 +142,7 @@ static void gpio_low_power(void)
 
 	const unsigned int num_pins =
 		(sizeof(pins_low_power) / sizeof(gpio_cfg_t));
-	int i;
-	for (i = 0; i < num_pins; i++) {
+	for (size_t i = 0; i < num_pins; i++) {
 		GPIO_OutClr(&pins_low_power[i]);
 		GPIO_Config(&pins_low_power[i]);
 	}