name exceptions consistently

Author: pschichtel

epoll/src/main/java/tel/schich/javacan/platform/linux/epoll/EPollSelector.java

@@ -95,8 +95,8 @@ public void close() throws IOException {
         IOException e = null;
         try {
             EPoll.close(epollfd);
-        } catch (LinuxNativeOperationException ex) {
-            e = ex;
+        } catch (LinuxNativeOperationException epollfdClose) {
+            e = epollfdClose;
         }
         try {
             EPoll.close(eventfd);