drm/vmwgfx: Fix copy-paste typo in validation

'entry' should be 'val' which is the loop iterator.

Fixes: 9e931f2e ("drm/vmwgfx: Refactor resource validation hashtable to use linux/hashtable implementation.")
Signed-off-by: Ian Forbes <ian.forbes@broadcom.com>
Reviewed-by: Zack Rusin <zack.rusin@broadcom.com>
Signed-off-by: Zack Rusin <zack.rusin@broadcom.com>
Link: https://lore.kernel.org/r/20250926195427.1405237-2-ian.forbes@broadcom.com