aio-posix: simplify aio_epoll_update

Extract common code out of the "if".
Reviewed-by: NFam Zheng <famz@redhat.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
Message-id: 20161108135524.25927-3-pbonzini@redhat.com
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>

aio-posix.c

@@ -81,29 +81,22 @@ static void aio_epoll_update(AioContext *ctx, AioHandler *node, bool is_new)
 {
     struct epoll_event event;
     int r;
+    int ctl;
 
     if (!ctx->epoll_enabled) {
         return;
     }
     if (!node->pfd.events) {
-        r = epoll_ctl(ctx->epollfd, EPOLL_CTL_DEL, node->pfd.fd, &event);
-        if (r) {
-            aio_epoll_disable(ctx);
-        }
+        ctl = EPOLL_CTL_DEL;
     } else {
         event.data.ptr = node;
         event.events = epoll_events_from_pfd(node->pfd.events);
-        if (is_new) {
-            r = epoll_ctl(ctx->epollfd, EPOLL_CTL_ADD, node->pfd.fd, &event);
-            if (r) {
-                aio_epoll_disable(ctx);
-            }
-        } else {
-            r = epoll_ctl(ctx->epollfd, EPOLL_CTL_MOD, node->pfd.fd, &event);
-            if (r) {
-                aio_epoll_disable(ctx);
-            }
-        }
+        ctl = is_new ? EPOLL_CTL_ADD : EPOLL_CTL_MOD;
+    }
+
+    r = epoll_ctl(ctx->epollfd, ctl, node->pfd.fd, &event);
+    if (r) {
+        aio_epoll_disable(ctx);
     }
 }