[POWERPC] EEH: hotplug recovery bugfix

If a device driver does not have native PCI error recovery,
a hotplug error recovery will be attemped. In this case,
the device driver will not report back whether its healthy
or not; simply assume that it is.

Signed-off-by: Linas Vepstas <linas@austin.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>