BUG/MINOR: log: properly free memory on logformat parse error and deinit()

This patch may be backported to all supported versions.
diff --git a/src/haproxy.c b/src/haproxy.c
index ec66103..93ce987 100644
--- a/src/haproxy.c
+++ b/src/haproxy.c
@@ -2249,11 +2249,15 @@
 
 		list_for_each_entry_safe(lf, lfb, &p->logformat, list) {
 			LIST_DEL(&lf->list);
+			release_sample_expr(lf->expr);
+			free(lf->arg);
 			free(lf);
 		}
 
 		list_for_each_entry_safe(lf, lfb, &p->logformat_sd, list) {
 			LIST_DEL(&lf->list);
+			release_sample_expr(lf->expr);
+			free(lf->arg);
 			free(lf);
 		}