When debug-threads is enabled, individual threads are given a separate
name (on Linux)

Fixes:
https://bugzilla.redhat.com/show_bug.cgi?id=1140121Signed-off-by: NMarc-André Lureau <marcandre.lureau@redhat.com>
Signed-off-by: NJiri Denemark <jdenemar@redhat.com>