Shorten the softirq kernel thread names because they always overflow the
limited comm length, appearing as "posix_cpu_timer" CPU# times.

Done on 2.6.24.7, but probably applicable to later kernels.
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>