nfsd4: preallocate open stateid in process_open1()

As with the nfs4_file, we'd prefer to find out about any failure before
creating a new file rather than after.

Signed-off-by: J. Bruce Fields <bfields@redhat.com>
diff --git a/fs/nfsd/xdr4.h b/fs/nfsd/xdr4.h
index 502dd43..ce8c591 100644
--- a/fs/nfsd/xdr4.h
+++ b/fs/nfsd/xdr4.h
@@ -229,6 +229,7 @@
 	int		op_truncate;        /* used during processing */
 	struct nfs4_openowner *op_openowner; /* used during processing */
 	struct nfs4_file *op_file;          /* used during processing */
+	struct nfs4_ol_stateid *op_stp;	    /* used during processing */
 	struct nfs4_acl *op_acl;
 };
 #define op_iattr	iattr