vdpa: ifcvf: return err when fail to request config irq

We ignore the err of requesting config interrupt, fix this.

Fixes: e7991f37 ("ifcvf: implement config interrupt in IFCVF")
Cc: Zhu Lingshan <lingshan.zhu@intel.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
Link: https://lore.kernel.org/r/20200723091254.20617-1-jasowang@redhat.com


Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Zhu Lingshan <lingshan.zhu@intel.com>
Fixes: e7991f37 ("ifcvf: implement config interrupt in IFCVF")
Cc: Zhu Lingshan <a class="moz-txt-link-rfc2396E" href="mailto:lingshan.zhu@intel.com">&lt;lingshan.zhu@intel.com&gt;</a>
Signed-off-by: Jason Wang <a class="moz-txt-link-rfc2396E" href="mailto:jasowang@redhat.com">&lt;jasowang@redhat.com&gt;</a>
Tested-by: Maxime Coquelin <maxime.coquelin@redhat.com>