Move the cleanup of the power domain HW state on the error path to the
same function where the corresponding init call was called from. I
noticed this problem when loading the module with load failure injection
enabled, making i915_load_modeset_init() fail.

CC: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Imre Deak <imre.deak@intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: http://patchwork.freedesktop.org/patch/msgid/1458128348-15730-19-git-send-email-imre.deak@intel.com