nfsd4: free_stateid can use the current stateid

Cc: Tigran Mkrtchyan <kofemann@gmail.com>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>

fs/nfsd/nfs4proc.c

@@ -1766,6 +1766,7 @@ static struct nfsd4_operation nfsd4_ops[] = {
 		.op_func = (nfsd4op_func)nfsd4_free_stateid,
 		.op_flags = ALLOWED_WITHOUT_FH | OP_MODIFIES_SOMETHING,
 		.op_name = "OP_FREE_STATEID",
+		.op_get_currentstateid = (stateid_getter)nfsd4_get_freestateid,
 		.op_rsize_bop = (nfsd4op_rsize)nfsd4_only_status_rsize,
 	},
 };