perf test: Add roundtrip test for hardware cache events

perf test: Add roundtrip test for hardware cache events

That nicely catches the problem reported by Joel Uckelman in
http://permalink.gmane.org/gmane.linux.kernel.perf.user/1016 :

  [root@sandy ~]# perf test
   1: vmlinux symtab matches kallsyms: Ok
   2: detect open syscall event: Ok
   3: detect open syscall event on all cpus: Ok
   4: read samples using the mmap interface: Ok
   5: parse events tests: Ok
   6: x86 rdpmc test: Ok
   7: Validate PERF_RECORD_* events & perf_sample fields: Ok
   8: Test perf pmu format parsing: Ok
   9: Test dso data interface: Ok
  10: roundtrip evsel->name check: FAILED!

  [root@sandy ~]# perf test -v 10
  10: roundtrip evsel->name check:
  --- start ---
  L1-dcache-misses != L1-dcache-load-misses
  L1-dcache-misses != L1-dcache-store-misses
  L1-dcache-misses != L1-dcache-prefetch-misses
  L1-icache-misses != L1-icache-load-misses
  L1-icache-misses != L1-icache-prefetch-misses
  LLC-misses != LLC-load-misses
  LLC-misses != LLC-store-misses
  LLC-misses != LLC-prefetch-misses
  dTLB-misses != dTLB-load-misses
  dTLB-misses != dTLB-store-misses
  dTLB-misses != dTLB-prefetch-misses
  iTLB-misses != iTLB-load-misses
  branch-misses != branch-load-misses
  node-misses != node-load-misses
  node-misses != node-store-misses
  node-misses != node-prefetch-misses
  ---- end ----
  roundtrip evsel->name check: FAILED!

  [root@sandy ~]#

Now lemme apply Jiri's fix and try it again...

Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Joel Uckelman <joel@lightboxtechnologies.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Namhyung Kim <namhyung@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-bbewtxw0rfipp5qy1j3jtg5d@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>