drm/amdkfd: fix list_del corruption in kfd_criu_resume_svm

drm/amdkfd: fix list_del corruption in kfd_criu_resume_svm

The cleanup tail of kfd_criu_resume_svm() walks
svms->criu_svm_metadata_list and kfree()s each struct criu_svm_metadata
without removing it from the list. The list head is left pointing at
freed kmalloc-96 objects.

A second AMDKFD_IOC_CRIU_OP from the same process re-enters: list_empty()
reads the dangling ->next (use-after-free), the loop walks freed entries,
and each is kfree()'d again (double-free). This is reachable by an
unprivileged render-group user via /dev/kfd with no capabilities required.

Add list_del() before the kfree() so the list is properly emptied. The
list_for_each_entry_safe() iterator already caches the next pointer, so
unlinking during the walk is safe.

Fixes: 2a909ae71871 ("drm/amdkfd: CRIU resume shared virtual memory ranges")
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
(cherry picked from commit 6322d278a298e2c1430b9d2697743d3a04b788b1)