CLEANUP: checks: Make desc argument to set_server_check_status const

This parameter is not modified by set_server_check_status() and
thus may be const.

Signed-off-by: Simon Horman <horms@verge.net.au>
diff --git a/src/checks.c b/src/checks.c
index fab13ed..820a8c2 100644
--- a/src/checks.c
+++ b/src/checks.c
@@ -198,7 +198,7 @@
  * Show information in logs about failed health check if server is UP
  * or succeeded health checks if server is DOWN.
  */
-static void set_server_check_status(struct server *s, short status, char *desc)
+static void set_server_check_status(struct server *s, short status, const char *desc)
 {
 	if (status == HCHK_STATUS_START) {
 		s->result = SRV_CHK_UNKNOWN;	/* no result yet */