xen/hvm: If we fail to fetch an HVM parameter print out which flag it is.

Makes it easier to troubleshoot in the field.

Acked-by: Ian Campbell <ian.campbell@citrix.com>
[v1: Use macro per Ian's suggestion]
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
1 file changed