vnode: drop comment, nonsensical where it is

[thib4711]

The line comment in struct vnode is fine;

diff --git sys/sys/vnode.h sys/sys/vnode.h
index 30787afddd8..b2f0fa4b60c 100644
--- sys/sys/vnode.h
+++ sys/sys/vnode.h
@@ -74,12 +74,7 @@ enum vtagtype        {
     "unused", "unused", "unused", "ISOFS", "unused",           \
     "EXT2FS", "VFS", "NTFS", "UDF", "FUSEFS", "TMPFS"
 
-/*
- * Each underlying filesystem allocates its own private area and hangs
- * it from v_data.  If non-null, this area is freed in getnewvnode().
- */
 LIST_HEAD(buflists, buf);
-
 RBT_HEAD(buf_rb_bufs, buf);
 
 struct namecache;