Taped drive thread name length restrictions

Summary

The maximum length for the name of a thread is 16 chars (15 + string termination char). Our drive names now are pretty long, to keep some relevant information in the thread name we should change the naming of the thread from the full name to the position of the drive to at least get some relevant information out of it.

What is the current bug behaviour?

[root@tpsrv454 ~]# pstree -a | grep cta-​
[...]
  |-cta-tpd-master --log-format=json --log-to-file=/var/log/cta/cta-taped-IBMLIB4-TS1160-F2C1R3.log--config=/etc/cta/cta-taped-IBML​
  |   |-cta-tpd-IBMLIB4 --log-format=json --log-to-file=/var/log/cta/cta-taped-IBMLIB4-TS1160-F2C1R3.log...​
  |   |   `-83*[{cta-tpd-IBMLIB4}]​
[...]

What is the new behaviour?

[root@tpsrv454 ~]# pstree -a | grep cta-​
[...]
  |-cta-tpd-master --log-format=json --log-to-file=/var/log/cta/cta-taped-IBMLIB4-TS1160-F2C1R3.log--config=/etc/cta/cta-taped-IBML​
  |   |-cta-tpd-IBMLIB4 --log-format=json --log-to-file=/var/log/cta/cta-taped-IBMLIB4-TS1160-F2C1R3.log...​
  |   |   `-83*[{cta-tpd-F2C1R3}]​
[...]