Merge pull request #3909 from thinkyhead/fix_array_inits

Fix some array initializations

Marlin/stepper.h

     //
     // 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

 #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