add refcnt using epoll_create to fix bug when use popen which dup the fd and close at end after epoll_create

Signed-off-by: dulibo1 <dulibo1@xiaomi.com>

fs/vfs/fs_epoll.c

@@ -246,6 +246,8 @@ static int epoll_do_create(int size, int flags)
       list_add_tail(&eph->free, &epn[i].node);
     }
 
+  eph->crefs++;
+
   /* Alloc the file descriptor */
 
   fd = file_allocate(&g_epoll_inode, flags, 0, eph, 0, true);