nfsd: Fix SP4_MACH_CRED negotiation in EXCHANGE_ID

 - don't BUG_ON() when not SP4_NONE
 - calculate recv and send reserve sizes correctly

Signed-off-by: Weston Andros Adamson <dros@netapp.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
diff --git a/fs/nfsd/nfs4proc.c b/fs/nfsd/nfs4proc.c
index 0d4c410..419572f 100644
--- a/fs/nfsd/nfs4proc.c
+++ b/fs/nfsd/nfs4proc.c
@@ -1524,7 +1524,7 @@
 static inline u32 nfsd4_exchange_id_rsize(struct svc_rqst *rqstp, struct nfsd4_op *op)
 {
 	return (op_encode_hdr_size + 2 + 1 + /* eir_clientid, eir_sequenceid */\
-		1 + 1 + 0 + /* eir_flags, spr_how, SP4_NONE (for now) */\
+		1 + 1 + 2 + /* eir_flags, spr_how, spo_must_enforce & _allow */\
 		2 + /*eir_server_owner.so_minor_id */\
 		/* eir_server_owner.so_major_id<> */\
 		XDR_QUADLEN(NFS4_OPAQUE_LIMIT) + 1 +\