nfsd: add dprintk of compound return

We already print each operation of the compound when debugging is turned
on; printing the result could also help with remote debugging.
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>

fs/nfsd/nfs4proc.c

@@ -952,6 +952,7 @@ encode_op:
 out:
 	nfsd4_release_compoundargs(args);
 	cstate_free(cstate);
+	dprintk("nfsv4 compound returned %d\n", ntohl(status));
 	return status;
 }