Platform device error handling cleanup

This patch is part of Juha Yrjola's earlier patch to add platform device
error handling and a BUG_ON to verify if host == NULL

Signed-off-by: Carlos Eduardo Aguiar <carlos.aguiar <at> indt.org.br>
Signed-off-by: Juha Yrjola <juha.yrjola <at> solidboot.com>
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>