perf stat: Expand metric+unit buffer size

Long metric names combined with units may exceed the metric_bf and
lead to truncation. Double metric_bf in size to avoid this.

Signed-off-by: Ian Rogers <[e-mail]>
Acked-by: Kan Liang <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Namhyung Kim <[e-mail]>

tools/perf/util/stat-shadow.c

···
 	if (!metric_events[i]) {
 		if (expr__parse(&ratio, pctx, metric_expr) == 0) {
 			char *unit;
-			char metric_bf[64];
+			char metric_bf[128];
 
 			if (metric_threshold &&
 			    expr__parse(&threshold, pctx, metric_threshold) == 0 &&