[4.1] a4f4d44 dont panic on pthread_cond_timedwait being interrupted

[Lasse Karstensen]

commit a4f4d44235caf03e221a1b692b227ff06438aa21
Author: Nils Goroll <nils.goroll at uplex.de>
Date:   Mon May 9 10:18:32 2016 +0200

    dont panic on pthread_cond_timedwait being interrupted
    
    As discussed with phk: Callers of Lck_CondWait with timeout should
    be prepared for early wakeups.

diff --git a/bin/varnishd/cache/cache_lck.c b/bin/varnishd/cache/cache_lck.c
index b702c2f..90190dc 100644
--- a/bin/varnishd/cache/cache_lck.c
+++ b/bin/varnishd/cache/cache_lck.c
@@ -198,7 +198,9 @@ Lck_CondWait(pthread_cond_t *cond, struct lock *lck, double when)
 		ts.tv_nsec = (long)(modf(when, &t) * 1e9);
 		ts.tv_sec = (long)t;
 		retval = pthread_cond_timedwait(cond, &ilck->mtx, &ts);
-		assert(retval == 0 || retval == ETIMEDOUT);
+		assert(retval == 0 ||
+		    retval == ETIMEDOUT ||
+		    retval == EINTR);
 	}
 	AZ(ilck->held);
 	ilck->held = 1;