proc_parse: Fix task name parsing

The task name may include spaces so %s
scanning format will fail (in particular
dumping rsyslogd fails since thread has
name "rs:main Q:Reg"). Fix it.

Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>