kernel: NFSv4: Fix free of uninitialized nfs4_label on referral lookup.

In the Linux kernel, the following vulnerability has been resolved: NFSv4: Fix free of uninitialized nfs4label on referral lookup. Send along the already-allocated fattr along with nfs4fslocations, and drop the memcpy of fattr. We end up growing two more allocations, but this fixes up a crash as:...