Fix vhost user assertion when sending more than one fd

If the client sends more than one region this assert triggers. The
reason is that two fd's are 8 bytes and VHOST_MEMORY_BASELINE_NREGIONS
is exactly 8.

The assert is wrong because it should not test for the size of the fd
array, but for the numbers of regions.

Signed-off-by: Christian Pötzsch <christian.poetzsch@kernkonzept.com>
Message-Id: <20240426083313.3081272-1-christian.poetzsch@kernkonzept.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

subprojects/libvhost-user/libvhost-user.c

@@ -568,7 +568,7 @@ vu_message_read_default(VuDev *dev, int conn_fd, VhostUserMsg *vmsg)
         if (cmsg->cmsg_level == SOL_SOCKET && cmsg->cmsg_type == SCM_RIGHTS) {
             fd_size = cmsg->cmsg_len - CMSG_LEN(0);
             vmsg->fd_num = fd_size / sizeof(int);
-            assert(fd_size < VHOST_MEMORY_BASELINE_NREGIONS);
+            assert(vmsg->fd_num <= VHOST_MEMORY_BASELINE_NREGIONS);
             memcpy(vmsg->fds, CMSG_DATA(cmsg), fd_size);
             break;
         }