Plug a leak in error exits from the match() function.

src/vmod_re2.c

@@ -711,6 +711,7 @@ vmod_match(VRT_CTX, struct vmod_priv *priv, VCL_STRING pattern,
 		if ((err = vre2_ngroups(vre2, &ngroups)) != NULL) {
 			VERR(ctx, "Cannot obtain number of capturing groups: "
 			     "%s", pattern, subject, err);
+			vre2_fini(&vre2);
 			return 0;
 		}
 		assert(ngroups >= 0);
@@ -720,6 +721,7 @@ vmod_match(VRT_CTX, struct vmod_priv *priv, VCL_STRING pattern,
 		    == NULL) {
 			VERRNOMEM(ctx, ERR_PREFIX "allocating match data",
 				  pattern, subject);
+			vre2_fini(&vre2);
 			return 0;
 		}
 		priv->priv = task_match;