drm/xe/devcoredump: Print errno if VM snapshot was not captured

My testing machine has only 8GB of RAM and while running piglit tests
I can reach the OOM cache in xe_vm_snapshot_capture() snap allocaiton
sometimes.

So to differentiate the OOM from race between capture and UMDs
unbinbind VMs here I'm adding a '[0].error: -12' to devcoredump.

v2:
- fix returned errno values

Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Reviewed-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Signed-off-by: José Roberto de Souza <jose.souza@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240307135229.41973-2-jose.souza@intel.com