char-socket: tcp_chr_recv(): add comment

Add comment, to stress that the order of operation (first drop old fds,
second check read status) is intended.

Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
diff --git a/chardev/char-socket.c b/chardev/char-socket.c
index b1ce5d0..1be078d 100644
--- a/chardev/char-socket.c
+++ b/chardev/char-socket.c
@@ -294,7 +294,12 @@
     }
 
     if (msgfds_num) {
-        /* close and clean read_msgfds */
+        /*
+         * Close and clean previous read_msgfds, they are obsolete at
+         * this point, regardless result of new call to
+         * qio_channel_readv_full().
+         */
+
         for (i = 0; i < s->read_msgfds_num; i++) {
             close(s->read_msgfds[i]);
         }