hw/cxl: Avoid accesses beyond the end of cel_log.

hw/cxl: Avoid accesses beyond the end of cel_log.

Add a check that the requested offset + length does not go beyond the end
of the cel_log.

Whilst the cci->cel_log is large enough to include all possible CEL
entries, the guest might still ask for entries beyond the end of it.
Move the comment to this new check rather than before the check on the
type of log requested.

Reported-by: Esifiel <esifiel@gmail.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Message-Id: <20241101133917.27634-7-Jonathan.Cameron@huawei.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>