perf_counter tools: Print 'CPU utilization factor' in builtin-stat

perf_counter tools: Print 'CPU utilization factor' in builtin-stat

Before:

 Performance counter stats for '/home/mingo/hackbench':

    5728.862689  task clock ticks     (msecs)
          34426  context switches     #        0.006 M/sec
           3835  CPU migrations       #        0.001 M/sec
          18158  pagefaults           #        0.003 M/sec
    16218109156  CPU cycles           #     2830.947 M/sec
    13519616840  instructions         #     2359.913 M/sec
       55941661  cache references     #        9.765 M/sec
       23554938  cache misses         #        4.112 M/sec

 Wall-clock time elapsed:   528.886980 msecs

After:

 Performance counter stats for '/home/mingo/hackbench':

    5845.443541  task clock ticks     #      11.886 CPU utilization factor
          38289  context switches     #       0.007 M/sec
           4208  CPU migrations       #       0.001 M/sec
          17755  pagefaults           #       0.003 M/sec
    16664668576  CPU cycles           #    2850.882 M/sec
    13468113991  instructions         #    2304.036 M/sec
       57445468  cache references     #       9.827 M/sec
       26896502  cache misses         #       4.601 M/sec

 Wall-clock time elapsed:   491.802357 msecs

Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: John Kacur <jkacur@redhat.com>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>