NFSD: return nfsv4 error code nfserr_notsupp rather than nfsv[23]'s nfserr_opnotsupp

Thanks for Bill Baker at sun.com for catching this
at Connectathon 2009.

This bug was introduced in 2.6.27
Signed-off-by: NBenny Halevy <bhalevy@panasas.com>
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

fs/nfsd/nfs4xdr.c

@@ -1005,7 +1005,7 @@ nfsd4_decode_noop(struct nfsd4_compoundargs *argp, void *p)
 static __be32
 nfsd4_decode_notsupp(struct nfsd4_compoundargs *argp, void *p)
 {
-	return nfserr_opnotsupp;
+	return nfserr_notsupp;
 }
 
 typedef __be32(*nfsd4_dec)(struct nfsd4_compoundargs *argp, void *);