Fix uninitialized return value in iomux_update_events

src/iomux_impl.c

@@ -142,16 +142,14 @@ int iomux_unregister_fd(struct IOMux *mux, struct IOMuxFD *fd)
 
 int iomux_update_events(struct IOMux *mux, struct IOMuxFD *fd, unsigned int what)
 {
-    int rc;
+    int rc = 0;
     assert(mux != NULL);
     assert(fd != NULL);
     assert(fd->callback != NULL);
     assert(fd->fd >= 0);
     
     if (fd->what != what) {
-        mux->ops.update_events_impl(mux, fd);
-    } else {
-        rc = 0;
+        rc = mux->ops.update_events_impl(mux, fd);
     }
 
     return rc;