eal: do not panic on PCI failures

eal: do not panic on PCI failures

Some devices may be inaccessible for a variety of reasons, or the
PCI-bus may be unavailable causing the whole thing to fail.  Still,
better to continue attempts at probes.

Since PCI isn't neccessarily required, it may be possible to simply log
the error and continue on letting the user check the logs and restart
the application when things have failed.

This will usually be an issue because of permissions.  However, it could
also be caused by OOM.  In either case, errno will contain the
underlying cause.

For linux, it is safe to re-init the system here, so allow the
application to take corrective action and reinit.

For BSD, this is not the case, for other reasons, including hugepage
allocation has already happened, and needs to be properly uninitialized.

Signed-off-by: Aaron Conole <aconole@redhat.com>
Acked-by: Bruce Richardson <bruce.richardson@intel.com>