logger: add pthread name
logger: add pthread name

The log message will be like:

2019-10-29 20:44:37.096 81774:tcmu-runner [CRIT] main:1398: Exiting...
2019-10-29 20:48:44.046 81979:dyn-config [CRIT] tcmu_set_log_level:106: log level now is DEBUG SCSI CMD
2019-10-29 20:48:44.046 81979:dyn-config [DEBUG] tcmu_resetup_log_file:734: No changes to current log_dir: /var/log, skipping it.
2019-10-29 20:48:44.050 81979:dyn-config [DEBUG] dyn_config_start:444: event->mask: 0x2

Signed-off-by: Xiubo Li <d6cd9ec469dfb11098caa077ea0b7b3220fc70dc@redhat.com>

open-iscsi/tcmu-runner,open-iscsi/tcmu-runner,agrover/tcmu-runner