drm/amdgpu: fix root reservation in amdgpu_vm_handle_fault
svm_range_restore_pages might reserve the root bo so it must
be called after unreserving it.
Fixes: 1b135c6da061 ("drm/amdgpu: extract amdgpu_vm_lock_by_pasid from amdgpu_vm_handle_fault")
Signed-off-by: Pierre-Eric Pelloux-Prayer <pierre-eric.pelloux-prayer@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
(cherry picked from commit
5cdc219fe86a1720aa4b5b4f42f11913146e6a93)