stats: Fix compiler warning about losing const

stats_statsd.c: In function ‘osmo_stats_reporter_statsd_send_item’:
stats_statsd.c:154:15: warning: initialization discards ‘const’ qualifier from pointer target type
  char *unit = desc->unit;
               ^

1 files changed, 1 insertions, 1 deletions

diff --git a/src/stats_statsd.c b/src/stats_statsd.c
index b93d90a7..28134109 100644
--- a/src/stats_statsd.c
+++ b/src/stats_statsd.c
@@ -151,7 +151,7 @@ static int osmo_stats_reporter_statsd_send_item(struct osmo_stats_reporter *srep
 	const struct osmo_stat_item_group *statg,
 	const struct osmo_stat_item_desc *desc, int value)
 {
-	char *unit = desc->unit;
+	const char *unit = desc->unit;
 
 	if (unit == OSMO_STAT_ITEM_NO_UNIT) {
 		unit = "g";