MINOR: threads: always place the clockid in the struct thread_info

It will be easier to deal with the internal API to always have it.
diff --git a/include/common/hathreads.h b/include/common/hathreads.h
index 0dbec67..6c420dd 100644
--- a/include/common/hathreads.h
+++ b/include/common/hathreads.h
@@ -50,6 +50,7 @@
 enum { tid = 0 };
 
 extern struct thread_info {
+	clockid_t clock_id;
 	/* pad to cache line (64B) */
 	char __pad[0];            /* unused except to check remaining room */
 	char __end[0] __attribute__((aligned(64)));
diff --git a/src/haproxy.c b/src/haproxy.c
index 692c333..1c5898e 100644
--- a/src/haproxy.c
+++ b/src/haproxy.c
@@ -2500,6 +2500,8 @@
 
 #ifdef USE_THREAD
 	pthread_getcpuclockid(pthread_self(), &thread_info[tid].clock_id);
+#else
+	thread_info[tid].clock_id = CLOCK_THREAD_CPUTIME_ID;
 #endif
 
 	tv_update_date(-1,-1);