fixes to catch proper netconf exception

- part of ONOS-7020

Change-Id: I55c02ca9fdb97f1ae12b4e3d7b76da565f9da741
diff --git a/drivers/fujitsu/src/main/java/org/onosproject/drivers/fujitsu/FujitsuVoltOnuOperConfig.java b/drivers/fujitsu/src/main/java/org/onosproject/drivers/fujitsu/FujitsuVoltOnuOperConfig.java
index 1af5e34..a126694 100644
--- a/drivers/fujitsu/src/main/java/org/onosproject/drivers/fujitsu/FujitsuVoltOnuOperConfig.java
+++ b/drivers/fujitsu/src/main/java/org/onosproject/drivers/fujitsu/FujitsuVoltOnuOperConfig.java
@@ -23,9 +23,9 @@
 import org.onosproject.net.driver.AbstractHandlerBehaviour;
 import org.onosproject.net.driver.DriverHandler;
 import org.onosproject.netconf.NetconfController;
+import org.onosproject.netconf.NetconfException;
 import org.slf4j.Logger;
 
-import java.io.IOException;
 import java.util.Set;
 
 import static com.google.common.base.Preconditions.checkNotNull;
@@ -88,7 +88,7 @@
                     .get(ncDeviceId)
                     .getSession()
                     .doWrappedRpc(request.toString());
-        } catch (IOException e) {
+        } catch (NetconfException e) {
             log.error("Cannot communicate to device {} exception {}", ncDeviceId, e);
         }
         return reply;
@@ -157,7 +157,7 @@
                     .get(ncDeviceId)
                     .getSession()
                     .doWrappedRpc(request.toString());
-        } catch (IOException e) {
+        } catch (NetconfException e) {
             log.error("Cannot communicate to device {} exception {}", ncDeviceId, e);
         }
         return reply;