[master] 7d93810ac issue vcl event through vcl_send_event()

[Nils Goroll]

commit 7d93810acfbf2437b82ec3b1aebef54d767f0190
Author: Nils Goroll <nils.goroll at uplex.de>
Date:   Tue Jan 21 17:06:14 2020 +0100

    issue vcl event through vcl_send_event()
    
    we were missing VCL_TaskEnter()/VCL_TaskLeave()
    
    Noticed working on #2902

diff --git a/bin/varnishd/cache/cache_vcl.c b/bin/varnishd/cache/cache_vcl.c
index 39dd7e112..2bd3f1eeb 100644
--- a/bin/varnishd/cache/cache_vcl.c
+++ b/bin/varnishd/cache/cache_vcl.c
@@ -540,7 +540,7 @@ vcl_set_state(VRT_CTX, const char *state)
 				vcl_BackendEvent(vcl, VCL_EVENT_WARM);
 				break;
 			}
-			AZ(vcl->conf->event_vcl(ctx, VCL_EVENT_COLD));
+			AZ(vcl_send_event(ctx, VCL_EVENT_COLD));
 			vcl->temp = VCL_TEMP_COLD;
 		}
 		break;