CA-58362: Host is not getting upgraded while performing Automatic upgrade through Rolling Pool Upgrade wizard
CA-58362: Host is not getting upgraded while performing Automatic upgrade through Rolling Pool Upgrade wizard

At the moment, XAPI plugins are throwing non-standardised exceptions, all of
which are caught by the XAPI plugin manager, which throws a single kind of
exception.

When a XAPI plugin threw a non-"SystemExit" exception, `XenAPIPlugin.py` would
rpcdump an exception message with error string `XENAPI_PLUGIN_EXCEPTION`;
however, this string is not a standard error string --- it appears that this
was a typo, since the string should have been `XENAPI_PLUGIN_FAILURE`. This
commit fixes this.

It appears that with a wrong error string rcpdump-ed, XenCenter would ignore
it altogether, making it seem that everything went ok.

A potential future improvement would be to modify XAPI plugins to throw
standardised errors, which would then be propagaded outside XAPI plugin
manager.

Signed-off-by: Rok Strnisa <ef2e6fb7f9c4d68ca2b20c62606309353789e818@citrix.com>

koushikcgit/xcp-rrdd,koushikcgit/xcp-rrdd,djs55/xcp-networkd,robhoes/squeezed,djs55/xcp-rrdd,djs55/xcp-rrdd,johnelse/xcp-rrdd,sharady/xcp-networkd,koushikcgit/xcp-rrdd,simonjbeaumont/xcp-rrdd,koushikcgit/xcp-networkd,djs55/xcp-networkd,sharady/xcp-networkd,koushikcgit/xcp-networkd,johnelse/xcp-rrdd,simonjbeaumont/xcp-rrdd,djs55/squeezed