CLEANUP: Make parameters of srv_downtime and srv_getinter const

The parameters of srv_downtime and srv_getinter are not modified
and thus may be const.

Signed-off-by: Simon Horman <horms@verge.net.au>
diff --git a/include/proto/server.h b/include/proto/server.h
index ded640a..b2df045 100644
--- a/include/proto/server.h
+++ b/include/proto/server.h
@@ -32,8 +32,8 @@
 #include <proto/queue.h>
 #include <proto/freq_ctr.h>
 
-int srv_downtime(struct server *s);
-int srv_getinter(struct server *s);
+int srv_downtime(const struct server *s);
+int srv_getinter(const struct server *s);
 
 /* increase the number of cumulated connections on the designated server */
 static void inline srv_inc_sess_ctr(struct server *s)
diff --git a/src/server.c b/src/server.c
index 98a9fbe..e542bb7 100644
--- a/src/server.c
+++ b/src/server.c
@@ -22,7 +22,7 @@
 	.list = LIST_HEAD_INIT(srv_keywords.list)
 };
 
-int srv_downtime(struct server *s)
+int srv_downtime(const struct server *s)
 {
 	if ((s->state & SRV_RUNNING) && s->last_change < now.tv_sec)		// ignore negative time
 		return s->down_time;
@@ -30,7 +30,7 @@
 	return now.tv_sec - s->last_change + s->down_time;
 }
 
-int srv_getinter(struct server *s)
+int srv_getinter(const struct server *s)
 {
 	if ((s->state & SRV_CHECKED) && (s->health == s->rise + s->fall - 1))
 		return s->inter;