perf tools: Ditch rtrim(), use skip_spaces() to get closer to the kernel

No change in behaviour, just using the same kernel idiom for such
operation.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: André Goddard Rosa <andre.goddard@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lkml.kernel.org/n/tip-a85lkptkt0ru40irpga8yf54@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
diff --git a/tools/perf/util/stat-display.c b/tools/perf/util/stat-display.c
index ce993d2..90df411 100644
--- a/tools/perf/util/stat-display.c
+++ b/tools/perf/util/stat-display.c
@@ -212,7 +212,7 @@ static void print_metric_csv(struct perf_stat_config *config __maybe_unused,
 		return;
 	}
 	snprintf(buf, sizeof(buf), fmt, val);
-	ends = vals = ltrim(buf);
+	ends = vals = skip_spaces(buf);
 	while (isdigit(*ends) || *ends == '.')
 		ends++;
 	*ends = 0;
@@ -280,7 +280,7 @@ static void print_metric_only_csv(struct perf_stat_config *config __maybe_unused
 		return;
 	unit = fixunit(tbuf, os->evsel, unit);
 	snprintf(buf, sizeof buf, fmt, val);
-	ends = vals = ltrim(buf);
+	ends = vals = skip_spaces(buf);
 	while (isdigit(*ends) || *ends == '.')
 		ends++;
 	*ends = 0;