r600: Only set context streamout strides info from the shader that has outputs

r600: Only set context streamout strides info from the shader that has outputs

With 5d517a streamout info is only attached to the shader for which the
transform feedback is actually recorded, but the driver set the context info
with each state submitted, thereby always using the info data that was
attached to the vertex shader.

Pass the streamout stride info to the context only from the shader that
actually has outputs. (Thanks to Marek Olšák for pointing me in the right
direction)

Fixes regresion with: dEQP-GLES31.functional.tessellation.invariance.*
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=108734
Fixes: 5d517a599b1eabd1d5696bf31e26f16568d35770
  st/mesa: Don't record garbage streamout information in the non-SSO case.

Signed-off-by: Gert Wollny <gert.wollny@collabora.com>
Reviewed-by: Dave Airlie <airlied@redhat.com>