Probing cycle and view build info bug fixes.

- Probing cycle would drop into a QUEUED state, if multiple G38.2 are
sent. It would not honor the auto cycle start flags. To fix, the auto
cycle start state is saved at the beginning of the probing cycle and
restored at the end, since the feed hold it uses to stop a triggered
probe will disable the auto start flag. For now it’s a patch, rather
than a permanent fix.

- protocol_buffer_synchronize() also has a failure case. Auto cycle
start does not get executed when the system is waiting in here, so if
it’s in a QUEUED state already, it won’t resume. Patched here, but not
fully resolved.

- Fixed a problem with the “view build info” command. The EEPROM write
would do weird things and corrupt the EEPROM. Not sure exactly what
caused it, but it’s likely a compiler problem with an improperly
defined EEPROM address. It didn’t have enough room to store a full
string. To fix, the build info EEPROM range was increased and the max
number of STARTUP_BLOCKS was reduced to 2 from 3.

- Lastly, when a $I view build info is used for the first time, it
would normally show an EEPROM read error, since it wasn’t cleared or
wasn’t therein the first place. It will now not show that error. A
patch rather than a permanent fix again.

motion_control.c

@@ -276,8 +276,12 @@ void mc_homing_cycle()
   void mc_probe_cycle(float *target, float feed_rate, uint8_t invert_feed_rate)
 #endif
 { 
+  // TODO: Need to update this cycle so it obeys a non-auto cycle start.
+  if (sys.state == STATE_CHECK_MODE) { return; }
+
   // Finish all queued commands and empty planner buffer before starting probe cycle.
   protocol_buffer_synchronize();
+  uint8_t auto_start_state = sys.auto_start; // Store run state
   
   // After syncing, check if probe is already triggered. If so, halt and issue alarm.
   if (probe_get_state()) { 
@@ -292,11 +296,10 @@ void mc_homing_cycle()
   #else
     mc_line(target, feed_rate, invert_feed_rate);
   #endif
-
-  // Activate the probing monitor in the stepper module.
-  // NOTE: Parser error-checking ensures the probe isn't already closed/triggered.
-  sys.probe_state = PROBE_ACTIVE;
   
+  // Activate the probing monitor in the stepper module.
+  sys.probe_state = PROBE_ACTIVE;
+
   // Perform probing cycle. Wait here until probe is triggered or motion completes.
   bit_true_atomic(sys.execute, EXEC_CYCLE_START);
   do {
@@ -304,7 +307,7 @@ void mc_homing_cycle()
     if (sys.abort) { return; } // Check for system abort
   } while ((sys.state != STATE_IDLE) && (sys.state != STATE_QUEUED));
 
-  // If motion completes without probe triggering, error out.
+  // Probing motion complete. If the probe has not been triggered, error out.
   if (sys.probe_state == PROBE_ACTIVE) { bit_true_atomic(sys.execute, EXEC_CRIT_EVENT); }
   protocol_execute_runtime();   // Check and execute run-time commands
   if (sys.abort) { return; } // Check for system abort
@@ -313,24 +316,8 @@ void mc_homing_cycle()
   st_reset(); // Reest step segment buffer.
   plan_reset(); // Reset planner buffer. Zero planner positions. Ensure probing motion is cleared.
   plan_sync_position(); // Sync planner position to current machine position.
-
-  // Probing motion is complete, but we'll pull-off triggered probe to the trigger location since
-  // we had to decelerate a little beyond it to stop the machine in a controlled manner.
-  uint8_t idx;
-  for(idx=0; idx<N_AXIS; idx++){
-    // NOTE: The target[] variable updated here will be sent back and synced with the g-code parser.
-    target[idx] = (float)sys.probe_position[idx]/settings.steps_per_mm[idx];
-  }
-  #ifdef USE_LINE_NUMBERS
-    mc_line(target, feed_rate, invert_feed_rate, line_number);
-  #else
-    mc_line(target, feed_rate, invert_feed_rate);
-  #endif
-
-  // Execute pull-off motion and wait until it completes.
-  bit_true_atomic(sys.execute, EXEC_CYCLE_START);
-  protocol_buffer_synchronize(); 
-  if (sys.abort) { return; } // Return if system reset has been issued.
+  
+  sys.auto_start = auto_start_state; // Restore run state.
 
   #ifdef MESSAGE_PROBE_COORDINATES
     // All done! Output the probe position as message.