Currently, the difference between warn_report_once() and
error_report_once() is the former has the "warning:" prefix, while the
latter does not have a similar level prefix.
At the meantime, considering that there is no error handling logic here,
and the purpose of error_report_once() is only to prompt the user with
an abnormal message, there is no need to use an error-level message here,
and instead we can just use a warning.
Therefore, downgrade the message in error_report_once() to warning, and
merge it into the previous warn_report_once().
Signed-off-by: Zhao Liu <zhao1.liu@intel.com>
Message-ID: <20240327103951.3853425-4-zhao1.liu@linux.intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>