perf stat: Display "none" for NaN with metric only json

Return earlier for an empty unit case. If snprintf of the fmt doesn't
produce digits between vals and ends, as happens with NaN, make the
value "none" as happens in print_metric_end.

Signed-off-by: Ian Rogers <[email protected]>
Acked-by: Namhyung Kim <[email protected]>
Cc: Yicong Yang <[email protected]>
Cc: Weilin Wang <[email protected]>
Cc: Will Deacon <[email protected]>
Cc: James Clark <[email protected]>
Cc: Mike Leach <[email protected]>
Cc: Leo Yan <[email protected]>
Cc: Sumanth Korikkar <[email protected]>
Cc: Thomas Richter <[email protected]>
Cc: Tim Chen <[email protected]>
Cc: John Garry <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Namhyung Kim <[email protected]>

0 files changed, 0 insertions, 0 deletions