perf report: Display names in s390 diagnostic counter sets

perf report: Display names in s390 diagnostic counter sets

On s390 the CPU Measurement Facility diagnostic counter sets are
displayed by counter number and value. Add the logical counter name in
the output (if it is available). Otherwise "unknown" is shown.

Output before:

 [root@s35lp76 perf]# ./perf report -D --stdio
 [00000000] Counterset:0 Counters:6
   Counter:000 Value:0x000000000085ec36 Counter:001 Value:0x0000000000796c94
   Counter:002 Value:0x0000000000005ada Counter:003 Value:0x0000000000092460
   Counter:004 Value:0x0000000000006073 Counter:005 Value:0x00000000001a9a73
 [0x000038] Counterset:1 Counters:2
   Counter:000 Value:0x000000000007c59f Counter:001 Value:0x000000000002fad6
 [0x000050] Counterset:2 Counters:16
   Counter:000 Value:000000000000000000 Counter:001 Value:000000000000000000

Output after:

    [root@s35lp76 perf]# ./perf report -D --stdio

 [00000000] Counterset:0 Counters:6
     Counter:000 cpu_cycles Value:0x000000000085ec36
     Counter:001 instructions Value:0x0000000000796c94
     Counter:002 l1i_dir_writes Value:0x0000000000005ada
     Counter:003 l1i_penalty_cycles Value:0x0000000000092460
     Counter:004 l1d_dir_writes Value:0x0000000000006073
     Counter:005 l1d_penalty_cycles Value:0x00000000001a9a73
 [0x000038] Counterset:1 Counters:2
     Counter:000 problem_state_cpu_cycles Value:0x000000000007c59f
     Counter:001 problem_state_instructions Value:0x000000000002fad6
 [0x000050] Counterset:2 Counters:16
     Counter:000 prng_functions Value:000000000000000000

Signed-off-by: Thomas Richter <tmricht@linux.ibm.com>
Reviewed-by: Hendrik Brueckner <brueckner@linux.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Link: http://lkml.kernel.org/r/20190117093003.96287-3-tmricht@linux.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>