NFSv4: Enable delegated opens even when reboot recovery is pending

Unlike the previous attempt, this takes into account the fact that
we may be calling it from the recovery thread itself. Detect this
by looking at what kind of open we're doing, and checking the state
of the NFS_DELEGATION_NEED_RECLAIM if it turns out we're doing a
reboot reclaim-type open.

Cc: Olga Kornievskaia <aglo@umich.edu>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>

include/linux/nfs_xdr.h

@@ -389,7 +389,7 @@ struct nfs_openargs {
 	const struct nfs_server *server;	 /* Needed for ID mapping */
 	const u32 *		bitmask;
 	const u32 *		open_bitmap;
-	__u32			claim;
+	enum open_claim_type4	claim;
 	enum createmode4	createmode;
 	const struct nfs4_label *label;
 };