Use smooth duty universally

Duty cycle can spike a lot, the purposes it's used for can all benefit
from the mild smoothing we already have. Unify the usage and only use
smooth duty for everything.

src/main.c

@@ -849,13 +849,13 @@ static void add_surge(data *d) {
     if (d->surge_enable) {
         float surge_now = 0;
 
-        if (d->motor.duty_smooth > d->float_conf.surge_duty_start + 0.04) {
+        if (d->motor.duty_cycle > d->float_conf.surge_duty_start + 0.04) {
             surge_now = d->surge_angle3;
             beep_alert(d, 3, 1);
-        } else if (d->motor.duty_smooth > d->float_conf.surge_duty_start + 0.02) {
+        } else if (d->motor.duty_cycle > d->float_conf.surge_duty_start + 0.02) {
             surge_now = d->surge_angle2;
             beep_alert(d, 2, 1);
-        } else if (d->motor.duty_smooth > d->float_conf.surge_duty_start) {
+        } else if (d->motor.duty_cycle > d->float_conf.surge_duty_start) {
             surge_now = d->surge_angle;
             beep_alert(d, 1, 1);
         }

src/motor_data.c

@@ -24,8 +24,6 @@
 #include <math.h>
 
 void motor_data_reset(MotorData *m) {
-    m->duty_smooth = 0;
-
     m->acceleration = 0;
     m->accel_idx = 0;
     for (int i = 0; i < 40; i++) {
@@ -52,8 +50,7 @@ void motor_data_update(MotorData *m) {
     m->current = VESC_IF->mc_get_tot_current_directional_filtered();
     m->braking = m->abs_erpm > 250 && sign(m->current) != m->erpm_sign;
 
-    m->duty_cycle = fabsf(VESC_IF->mc_get_duty_cycle_now());
-    m->duty_smooth = m->duty_smooth * 0.9f + m->duty_cycle * 0.1f;
+    m->duty_cycle = m->duty_cycle * 0.9f + fabsf(VESC_IF->mc_get_duty_cycle_now()) * 0.1f;
 
     float current_acceleration = m->erpm - m->last_erpm;
     m->last_erpm = m->erpm;

src/motor_data.h

@@ -34,7 +34,6 @@ typedef struct {
     bool braking;
 
     float duty_cycle;
-    float duty_smooth;
 
     // an average calculated over last ACCEL_ARRAY_SIZE values
     float acceleration;