Current perf diff result is somewhat confusing since it sometimes hide
small result and sometimes there's no result.  So do not hide small
result (less than 0.01%) and print "N/A" if baseline is not
recorded (for ratio and wdiff only).  Blank means the baseline is
available but its pairs are not.

Before:

  # Baseline    Delta  Shared Object      Symbol
  # ........  .......  .................  .........................
  #
       ...
       0.01%   -0.01%  [kernel.kallsyms]  [k] native_write_msr_safe
       0.01%           [kernel.kallsyms]  [k] scheduler_tick
       0.01%           [kernel.kallsyms]  [k] native_read_msr_safe
       0.00%           [kernel.kallsyms]  [k] __rcu_read_unlock
                       [kernel.kallsyms]  [k] _raw_spin_lock
               +0.01%  [kernel.kallsyms]  [k] apic_timer_interrupt
                       [kernel.kallsyms]  [k] read_tsc

After:

  # Baseline    Delta  Shared Object      Symbol
  # ........  .......  .................  .........................
  #
       ...
       0.01%   -0.01%  [kernel.kallsyms]  [k] native_write_msr_safe
       0.01%           [kernel.kallsyms]  [k] scheduler_tick
       0.01%           [kernel.kallsyms]  [k] native_read_msr_safe
       0.00%           [kernel.kallsyms]  [k] __rcu_read_unlock
               +0.01%  [kernel.kallsyms]  [k] _raw_spin_lock
               +0.01%  [kernel.kallsyms]  [k] apic_timer_interrupt
               +0.01%  [kernel.kallsyms]  [k] read_tsc
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1419656793-32756-3-git-send-email-namhyung@kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>