configure: Improve Xen autodetection for hosts without Xen

With this patch, it only takes one test (instead of four)
to detect that there is no Xen support at all.

For most build hosts, this will reduce the time configure needs.
It will also reduce noisy output in config.log.

Build hosts with Xen now need up to five (instead of up to four)
tests. They get improved diagnostics when Xen support fails.

Cc: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Signed-off-by: Stefan Weil <sw@weilnetz.de>
Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>

0 files changed, 0 insertions, 0 deletions