Add a couple of asserts to explain stuff to Coverity

bin/varnishd/cache/cache_esi_parse.c

@@ -926,6 +926,7 @@ VEP_Parse(const struct busyobj *bo, const char *p, size_t l)
 			 * Match against a table while split over input
 			 * sections.
 			 */
+			AN(vep->match);
 			do {
 				if (*p == '>') {
 					for (vm = vep->match;

bin/varnishd/storage/storage_persistent_subr.c

@@ -139,6 +139,7 @@ smp_reset_sign(struct smp_signctx *ctx)
 {
 
 	memset(ctx->ss, 0, sizeof *ctx->ss);
+	assert(strlen(ctx->id) < sizeof *ctx->ss);
 	strcpy(ctx->ss->ident, ctx->id);
 	ctx->ss->unique = ctx->unique;
 	ctx->ss->mapped = (uintptr_t)ctx->ss;