multi-process: Avoid logical AND of mutually exclusive tests

Fixes an if statement that performs a logical AND of mutually exclusive
tests

Buglink: https://bugs.launchpad.net/qemu/+bug/1926995
Reviewed-by: Thomas Huth <thuth@redhat.com>
Signed-off-by: Jagannathan Raman <jag.raman@oracle.com>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-Id: <1620402803-9237-1-git-send-email-jag.raman@oracle.com>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>

hw/remote/mpqemu-link.c

@@ -218,7 +218,7 @@ uint64_t mpqemu_msg_send_and_await_reply(MPQemuMsg *msg, PCIProxyDev *pdev,
 
 bool mpqemu_msg_valid(MPQemuMsg *msg)
 {
-    if (msg->cmd >= MPQEMU_CMD_MAX && msg->cmd < 0) {
+    if (msg->cmd >= MPQEMU_CMD_MAX || msg->cmd < 0) {
         return false;
     }