vfs: temporarily revert r351825

There are 2 problems:

• it introduces a funny bug where it can end up trylocking the same vnode [1]
• it exposes a pre-existing softdep deadlock [2]

Both are easier to run into that the bug which got fixed, so revert until
a complete solution is worked out.

Reported by: cy [1], pho [2]
Sponsored by: The FreeBSD Foundation