virCommand: Extend debug message for handshake

Currently, we are logging only one side of pipes we
create in virCommandRequireHandshake(); This is enough
in cases where pipe2() returns two consecutive FDs. However,
it is not guaranteed and it may return any FDs.
Therefore, it's wise to log the other ends as well.
(cherry picked from commit 7454849e)

src/util/command.c

@@ -2443,8 +2443,10 @@ void virCommandRequireHandshake(virCommandPtr cmd)
         return;
     }
 
-    VIR_DEBUG("Transfer handshake wait=%d notify=%d",
-              cmd->handshakeWait[1], cmd->handshakeNotify[0]);
+    VIR_DEBUG("Transfer handshake wait=%d notify=%d, "
+              "keep handshake wait=%d notify=%d",
+              cmd->handshakeWait[1], cmd->handshakeNotify[0],
+              cmd->handshakeWait[0], cmd->handshakeNotify[1]);
     virCommandTransferFD(cmd, cmd->handshakeWait[1]);
     virCommandTransferFD(cmd, cmd->handshakeNotify[0]);
     cmd->handshake = true;