If the user does not have permissions to send ioctls to the device (due to
SELinux or cgroups, for example), the output can look like
qemu-kvm: -device scsi-block,drive=disk: cannot get SG_IO version number:
Operation not permitted. Is this a SCSI device?
but this is confusing because the ioctl was blocked _before_ the device
even received the SG_GET_VERSION_NUM ioctl. Therefore, for EPERM errors
the suggestion should be eliminated. To make that simpler, change the
code to use error_append_hint.
Reported-by: Ala Hino <ahino@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>