drm/i915/guc: Don't forget to free GuC error log

We're freeing GuC error log in uc_fini_hw() that matches
corresponding uc_init_hw() but we missed the point that this
log object is copied on error path and in case of failure in
uc_init_hw() we will leak this object as uc_fini_hw() is
never called.

If we free this log object as part of the late uC cleanup, where
we also release other firmware objects, we can avoid this BUG:

[70841.001413] BUG drm_i915_gem_object (Tainted: G     U  W       ): Objects remaining in drm_i915_gem_object on __kmem_cache_shutdown()
[70841.001436] INFO: Slab 0x00000000c94e41af objects=21 used=1 fp=0x000000001d60c40a flags=0x8000000000008100

[70841.001466] Call Trace:
[70841.001471]  dump_stack+0x5e/0x8e
[70841.001476]  slab_err+0x99/0xb0
[70841.001483]  ? __slab_alloc.isra.24.constprop.29+0x62/0x70
[70841.001491]  ? __kmalloc+0x1f5/0x320
[70841.001497]  __kmem_cache_shutdown+0x18b/0x400
[70841.001505]  shutdown_cache+0x13/0x1c0
[70841.001511]  kmem_cache_destroy+0x1c2/0x240
[70...

drivers/gpu/drm/i915/intel_uc.c

@@ -27,6 +27,8 @@
 #include "intel_guc.h"
 #include "i915_drv.h"
 
+static void guc_free_load_err_log(struct intel_guc *guc);
+
 /* Reset GuC providing us with fresh state for both GuC and HuC.
  */
 static int __intel_uc_reset_hw(struct drm_i915_private *dev_priv)
@@ -183,6 +185,8 @@ void intel_uc_fini_fw(struct drm_i915_private *dev_priv)
 
 	if (USES_HUC(dev_priv))
 		intel_uc_fw_fini(&dev_priv->huc.fw);
+
+	guc_free_load_err_log(&dev_priv->guc);
 }
 
 /**
@@ -428,8 +432,6 @@ void intel_uc_fini_hw(struct drm_i915_private *dev_priv)
 {
 	struct intel_guc *guc = &dev_priv->guc;
 
-	guc_free_load_err_log(guc);
-
 	if (!USES_GUC(dev_priv))
 		return;