monitor: Prevent removing fd from set during init If an fd is added to an fd set via the command line, and it is not referenced by another command line option (ie. -drive), then clean it up after QEMU initialization is complete. Signed-off-by: Corey Bryant <coreyb@linux.vnet.ibm.com> Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>