The zoffset and depth values were not being considered when calling
error_check_subtexture_dimensions().
Fixes 2 dEQP tests:
* dEQP-GLES3.functional.negative_api.texture.texsubimage3d_neg_offset
* dEQP-GLES3.functional.negative_api.texture.texsubimage3d_invalid_offset
Reviewed-by: Brian Paul <brianp@vmware.com>
Reviewed-by: Ian Romanick <ian.d.romanick@intel.com>
Cc: "10.4 10.5" <mesa-stable@lists.freedestkop.org>