EthCalibrator: fixed CheckHwFault

[valegagge]

During the investigation of this ticket, @MSECode and I noticed some bugs in the Ethernet calibrator.

1. there is an empty debug string: DEBUG] Left_Arm_Calibrator : Joints calibration order:
2. the checkHWFault function performed a loop on the joints in (0, totJointsToCalibrate) range instead of on the list containing the required joints.
3. the return value of checkHWFault function was ignored.

We fixed them in this way:
1.

2. the loop in performed on the elements containing in the list of joints to calibrate

Before	After

3. Added a check on the return value of checkHWFault function
   

Results:

Here there are the logs of the left arm during calibration where the joint number 9 is omitted

Before

[DEBUG] left_arm-calibrator starting calibration of device left_arm-mc_remapper
[INFO] Left_Arm_Calibrator : starting calibration
[ERROR] Left_Arm_Calibrator cannot perform 'check hardware fault' operation because joint number 9 is out of range [].
[DEBUG] Left_Arm_Calibrator : Joints calibration order:
[WARNING] Left_Arm_Calibrator  is calibrating only a subset of the robot part. 

After

[DEBUG] left_arm-calibrator starting calibration of device left_arm-mc_remapper
[INFO] Left_Arm_Calibrator : starting calibration
[DEBUG] Left_Arm_Calibrator : Joints calibration order: 4 5 6 3 2 0 1 7 8 10 11 12
[WARNING] Left_Arm_Calibrator  is calibrating only a subset of the robot part. Calibrating  12  over a total of  13

[pattacini]

Fine with me 👍🏻
I'll wait a short while to see whether @marcoaccame is available for a second review.

[marcoaccame]

OK by me