HBASE-453 undeclared throwable exception from HTable.get

Instead of wrapping UndeclaredThrowableException in a new IOException, wrap UndeclaredThrowableException.getCause

git-svn-id: https://svn.apache.org/repos/asf/hadoop/hbase/trunk@654267 13f79535-47bb-0310-9956-ffa450edef68

src/java/org/apache/hadoop/hbase/ipc/HbaseRPC.java

@@ -219,7 +219,7 @@ public class HbaseRPC {
           e = (IOException) t;
         } else {
           e = new IOException("error during RPC call");
-          e.initCause(t);
+          e.initCause(t.getCause());
         }
         throw e;
       }