According to: https://spdx.org/ids-how, let's still allow QEMU to use
the SPDX license identifier:
// SPDX-License-Identifier: ***
CC: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Peter Xu <peterx@redhat.com>
Message-Id: <20190426062705.4651-1-peterx@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>