[master] a6ce0697c Avoid use after free.

[Poul-Henning Kamp]

commit a6ce0697cd7be9a7fabb605af0a6a5dda7f8ce62
Author: Poul-Henning Kamp <phk at FreeBSD.org>
Date:   Mon May 27 11:35:32 2019 +0000

    Avoid use after free.
    
    Spotted by:     fgs with asan (in the castle)

diff --git a/bin/varnishd/mgt/mgt_vcl.c b/bin/varnishd/mgt/mgt_vcl.c
index 892605630..4347a3abd 100644
--- a/bin/varnishd/mgt/mgt_vcl.c
+++ b/bin/varnishd/mgt/mgt_vcl.c
@@ -247,6 +247,7 @@ mgt_vcl_del(struct vclprog *vp)
 		VJ_master(JAIL_MASTER_LOW);
 		free(vp->fname);
 	}
+	mgt_vcl_symtab_clean(vp);
 	while (!VTAILQ_EMPTY(&vp->vmods)) {
 		vd = VTAILQ_FIRST(&vp->vmods);
 		CHECK_OBJ(vd, VMODDEP_MAGIC);
@@ -265,7 +266,6 @@ mgt_vcl_del(struct vclprog *vp)
 		}
 	}
 	free(vp->name);
-	mgt_vcl_symtab_clean(vp);
 	FREE_OBJ(vp);
 }