Demoting log regarding interrupt exception to warning.

Change-Id: Iae06ae0f2d5e8a807dc564ee8c64e2982fe9726f
diff --git a/protocols/openflow/ctl/src/main/java/org/onosproject/openflow/controller/impl/OFChannelHandler.java b/protocols/openflow/ctl/src/main/java/org/onosproject/openflow/controller/impl/OFChannelHandler.java
index 01b4f1a..4ee0372 100644
--- a/protocols/openflow/ctl/src/main/java/org/onosproject/openflow/controller/impl/OFChannelHandler.java
+++ b/protocols/openflow/ctl/src/main/java/org/onosproject/openflow/controller/impl/OFChannelHandler.java
@@ -1633,7 +1633,7 @@
                         processMessages(tc);
                     }
                 } catch (InterruptedException e) {
-                    log.error("executor thread InterruptedException: {}", e);
+                    log.warn("Dispatcher interrupted");
                     Thread.currentThread().interrupt();
                     // interrupted. gracefully shutting down
                     return;