Fix PR 303: msdosfs: moving a file into another directory causes panic.
" ... the code that does the rename already has the denode
locked when msdosfs_hashins() gets called, resulting in the panic
when the routine attempts to lock the denode again.
...
The attached patch changes the msdosfs_hashins() routine to not lock the
denode. The caller is now resposible for obtaining the lock instead
of having msdosfs_hashins() do it for them."
2360b9bfc7