i915_gem_object_create_lmem_from_data() lacks the flush of the data
written to lmem to ensure the object is marked as dirty and the writes
flushed to the backing store. Once created, we can immediately release
the obj->mm.mapping caching of the vmap.

Fixes: 7acbbc7c ("drm/i915/guc: put all guc objects in lmem when available")
Cc: Matthew Auld <matthew.auld@intel.com>
Cc: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Cc: Andi Shyti <andi.shyti@linux.intel.com>
Cc: Matthew Brost <matthew.brost@intel.com>
Cc: John Harrison <John.C.Harrison@Intel.com>
Signed-off-by: Chris Wilson <chris.p.wilson@linux.intel.com>
Cc: <stable@vger.kernel.org> # v5.16+
Signed-off-by: Nirmoy Das <nirmoy.das@intel.com>
Reviewed-by: Andi Shyti <andi.shyti@linux.intel.com>
Reviewed-by: Nirmoy Das <nirmoy.das@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230316165918.13074-1-nirmoy.das@intel.com
(cherry picked from commit e2ee1047)
Signed-off-by: Jani Nikula <jani.nikula@intel.com>