perf lock contention: Fix debug stat if no contention

It should not divide if the total number is 0.  Otherwise it'd show
NaN in the bad rate output.  Also add a whitespace in the "output
for debug" message.

  $ sudo perf lock contention -abv true
  Looking at the vmlinux_path (8 entries long)
  symsrc__init: cannot get elf header.
  Using /proc/kcore for kernel data
  Using /proc/kallsyms for symbols
   contended   total wait     max wait     avg wait         type   caller

  === output for debug===

  bad: 0, total: 0
  bad rate: -nan %     <-------------------------  (here)
  histogram of events caused bad sequence
      acquire: 0
     acquired: 0
    contended: 0
      release: 0

Signed-off-by: Namhyung Kim <[email protected]>
Cc: Adrian Hunter <[email protected]>
Cc: Hao Luo <[email protected]>
Cc: Ian Rogers <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: [email protected]
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>

0 files changed, 0 insertions, 0 deletions