drm/i915: Fix error path in i915_drm_resume_early

If system resume fails, this may lead to a runtime PM wake reference
underflow used for runtime PM state checking.

Fixes: 1f814daca43a ("drm/i915: add support for checking if we hold an RPM reference")
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/1460963062-13211-2-git-send-email-imre.deak@intel.com

drivers/gpu/drm/i915/i915_drv.c

@@ -842,11 +842,11 @@ static int i915_drm_resume_early(struct drm_device *dev)
 	    !(dev_priv->suspended_to_idle && dev_priv->csr.dmc_payload))
 		intel_power_domains_init_hw(dev_priv, true);
 
+	enable_rpm_wakeref_asserts(dev_priv);
+
 out:
 	dev_priv->suspended_to_idle = false;
 
-	enable_rpm_wakeref_asserts(dev_priv);
-
 	return ret;
 }