NFS: Return meaningful status from decode_secinfo()

When compiling, I was getting this warning:
fs/nfs/nfs4xdr.c: In function ‘decode_secinfo’:
fs/nfs/nfs4xdr.c:4839:6: warning: variable ‘status’ set but not used
[-Wunused-but-set-variable]

We were unconditionally returning 0 as long as there wasn't an error
coming out of xdr_inline_decode().  We probably want to check the error
status coming out of decode_op_hdr() and decode_secinfo_gss(), rather
than assuming that everything is OK all the time.

Signed-off-by: Bryan Schumaker <bjschuma@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

fs/nfs/nfs4xdr.c

@@ -4836,6 +4836,8 @@ static int decode_secinfo(struct xdr_stream *xdr, struct nfs4_secinfo_res *res)
 	int i, num_flavors;
 
 	status = decode_op_hdr(xdr, OP_SECINFO);
+	if (status)
+		goto out;
 	p = xdr_inline_decode(xdr, 4);
 	if (unlikely(!p))
 		goto out_overflow;
@@ -4854,14 +4856,15 @@ static int decode_secinfo(struct xdr_stream *xdr, struct nfs4_secinfo_res *res)
 		sec_flavor->flavor = be32_to_cpup(p);
 
 		if (sec_flavor->flavor == RPC_AUTH_GSS) {
-			if (decode_secinfo_gss(xdr, sec_flavor))
-				break;
+			status = decode_secinfo_gss(xdr, sec_flavor);
+			if (status)
+				goto out;
 		}
 		res->flavors->num_flavors++;
 	}
 
-	return 0;
-
+out:
+	return status;
 out_overflow:
 	print_overflow_msg(__func__, xdr);
 	return -EIO;