audit-util: check correct errno

(cherry picked from commit 190a095)
(cherry picked from commit c90ae08)
(cherry picked from commit a3872e6)
(cherry picked from commit 4503a6d)

Author: YHNdnzj

src/basic/audit-util.c

@@ -101,7 +101,7 @@ static int try_audit_request(int fd) {
 
         n = recvmsg_safe(fd, &mh, 0);
         if (n < 0)
-                return -errno;
+                return n;
         if (n != NLMSG_LENGTH(sizeof(struct nlmsgerr)))
                 return -EIO;