NFS: added FREE_STATEID call

FREE_STATEID is used to tell the server that we want to free a stateid
that no longer has any locks associated with it.  This allows the client
to reclaim locks without encountering edge conditions documented in
section 8.4.3 of RFC 5661.

Signed-off-by: Bryan Schumaker <bjschuma@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
diff --git a/include/linux/nfs4.h b/include/linux/nfs4.h
index efe07f7..a3c4bc8 100644
--- a/include/linux/nfs4.h
+++ b/include/linux/nfs4.h
@@ -565,6 +565,7 @@
 	NFSPROC4_CLNT_LAYOUTRETURN,
 	NFSPROC4_CLNT_SECINFO_NO_NAME,
 	NFSPROC4_CLNT_TEST_STATEID,
+	NFSPROC4_CLNT_FREE_STATEID,
 };
 
 /* nfs41 types */