Revert "fs/9p: fix uaf in in v9fs_stat2inode_dotl"

This reverts commit 11763a85.

This is a requirement to revert commit 724a0845 ("fs/9p: simplify
iget to remove unnecessary paths"), see that revert for details.

Fixes: 724a0845 ("fs/9p: simplify iget to remove unnecessary paths")
Reported-by: Will Deacon <will@kernel.org>
Link: https://lkml.kernel.org/r/20240923100508.GA32066@willie-the-truck


Cc: stable@vger.kernel.org # v6.9+
Message-ID: <20241024-revert_iget-v1-3-4cac63d25f72@codewreck.org>
Signed-off-by: Dominique Martinet <asmadeus@codewreck.org>