i965: fix transform feedback with primitive restart

i965: fix transform feedback with primitive restart

When querying GL_PRIMITIVES_GENERATED, if primitive restart
is also used, then take the software primitive restart
path so GL_PRIMITIVES_GENERATED is returned correctly.

GL_TRANSFORM_FEEDBACK_PRIMITIVES_WRITTEN is also updated
since it will also affected by the same issue.

As noted in brw_primitive_restart.c, with further work we
should be able to move this situation back to a hardware
handled path.

Signed-off-by: Jordan Justen <jordan.l.justen@intel.com>
Reviewed-by: Ian Romanick <ian.d.romanick@intel.com>
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>