Fix some of array initializations

- In `stepper.h` init `count_direction` array
- In `ultralcd.cpp` init `autotune_temp` array

Marlin/stepper.h

@@ -139,7 +139,7 @@ class Stepper {
     //
     // Current direction of stepper motors (+1 or -1)
     //
-    volatile signed char count_direction[NUM_AXIS] = { 1 };
+    volatile signed char count_direction[NUM_AXIS] = { 1, 1, 1, 1 };
 
   public:
 

Marlin/ultralcd.cpp

@@ -1369,7 +1369,7 @@ static void lcd_control_menu() {
 #if ENABLED(PID_AUTOTUNE_MENU)
 
   #if ENABLED(PIDTEMP)
-    int autotune_temp[EXTRUDERS] = { 150 };
+    int autotune_temp[EXTRUDERS] = ARRAY_BY_EXTRUDERS1(150);
     const int heater_maxtemp[EXTRUDERS] = ARRAY_BY_EXTRUDERS(HEATER_0_MAXTEMP, HEATER_1_MAXTEMP, HEATER_2_MAXTEMP, HEATER_3_MAXTEMP);
   #endif