perf script: Show hw-cache events

perf script: Show hw-cache events

'perf script' fails to report hardware cache events (PERF_TYPE_HW_CACHE)
where as 'perf report' shows the samples. Fix it. Ex,

  # perf record -e L1-dcache-loads ./a.out
  [ perf record: Woken up 1 times to write data ]
  [ perf record: Captured and wrote 0.008 MB perf.data (11 samples)]

Before patch:

  # perf script | wc -l
  0

After patch:

  # perf script | wc -l
  11

Committer testing:

  [root@jouet ~]# perf script | head -30 | tail
        Timer 9803 [2] 8.963330:  1554 L1-dcache-loads: 7ffef89baae4 __vdso_clock_gettime+0xf4 ([vdso])
      swapper    0 [2] 8.963343:  5626 L1-dcache-loads: ffffffffa66f4f6b cpuidle_not_av+0xb (/lib/modules/4.17.0-rc5/build/vmlinux)
      firefox 4853 [2] 8.964070: 18935 L1-dcache-loads: 7f0b9a00dc30 xcb_poll_for_event+0x0 (/usr/lib64/libxcb.so.1.1.0)
  Softwar~cTh 4928 [2] 8.964548: 15928 L1-dcache-loads: ffffffffa60d795c update_curr+0x10c (/lib/modules/4.17.0-rc5/build/vmlinux)
      firefox 4853 [2] 8.964675: 14978 L1-dcache-loads: ffffffffa6897018 mutex_unlock+0x18 (/lib/modules/4.17.0-rc5/build/vmlinux)
  gnome-shell 2026 [3] 8.964693: 50670 L1-dcache-loads: 7fa08854de6d g_source_iter_next+0x6d (/usr/lib64/libglib-2.0.so.0.5400.3)
   Compositor 4929 [1] 8.964784: 71772 L1-dcache-loads: 7f0b936bf078 [unknown] (/usr/lib64/firefox/libxul.so)
     Xwayland 2096 [2] 8.964919: 16799 L1-dcache-loads: 7f68ce2fcb8a glXGetCurrentContext+0x1a (/usr/lib64/libGLX.so.0.0.0)
  gnome-shell 2026 [3] 8.964997: 50670 L1-dcache-loads: 7fa08854de6d g_source_iter_next+0x6d (/usr/lib64/libglib-2.0.so.0.5400.3)
  [root@jouet ~]#

Signed-off-by: Seeteena Thoufeek <s1seetee@linux.vnet.ibm.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1528455748-20087-1-git-send-email-s1seetee@linux.vnet.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>